diff --git a/.github/workflows/nightly-artifacts.yml b/.github/workflows/nightly-artifacts.yml
index 51b7b2e..a3a24db 100644
--- a/.github/workflows/nightly-artifacts.yml
+++ b/.github/workflows/nightly-artifacts.yml
@@ -12,7 +12,7 @@ env:
   FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true
 
 permissions:
-  contents: write
+  contents: read
   packages: write
 
 jobs:
@@ -34,11 +34,11 @@ jobs:
           Add-Content -Path $env:GITHUB_ENV -Value "SHORT_SHA=$shortSha"
           Add-Content -Path $env:GITHUB_ENV -Value "ASSET_BASENAME=praktiKST-$version-$shortSha"
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Install WiX Toolset
         shell: pwsh
@@ -89,11 +89,11 @@ jobs:
           SHORT_SHA="${GITHUB_SHA::7}"
           echo "ASSET_BASENAME=KST4Contest-${VERSION}-${SHORT_SHA}" >> "$GITHUB_ENV"
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Ensure mvnw is executable
         run: chmod +x mvnw
@@ -169,11 +169,11 @@ jobs:
           SHORT_SHA="${GITHUB_SHA::7}"
           echo "ASSET_BASENAME=KST4Contest-${VERSION}-${SHORT_SHA}" >> "$GITHUB_ENV"
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Install packaging dependencies
         run: |
@@ -199,7 +199,6 @@ jobs:
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
             --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec \
-            --linux-package-deps "libgstreamer1.0-0,libgstreamer-plugins-base1.0-0,gstreamer1.0-plugins-good" \
             --dest dist
           DEB="$(ls dist/*.deb | head -n 1)"
           if [ -z "$DEB" ]; then
@@ -228,11 +227,11 @@ jobs:
           SHORT_SHA="${GITHUB_SHA::7}"
           echo "ASSET_BASENAME=KST4Contest-${VERSION}-${SHORT_SHA}" >> "$GITHUB_ENV"
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Install packaging dependencies
         run: |
@@ -258,7 +257,6 @@ jobs:
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
             --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec \
-            --linux-package-deps "gstreamer1,gstreamer1-plugins-base,gstreamer1-plugins-good" \
             --dest dist
           RPM="$(ls dist/*.rpm | head -n 1)"
           if [ -z "$RPM" ]; then
@@ -289,11 +287,11 @@ jobs:
           echo "SHORT_SHA=$SHORT_SHA" >> "$GITHUB_ENV"
           echo "ASSET_BASENAME=KST4Contest-${VERSION}-${SHORT_SHA}" >> "$GITHUB_ENV"
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Install packaging dependencies
         run: |
@@ -348,42 +346,21 @@ jobs:
           if [ -f "$PKGROOT/usr/lib/KST4Contest/lib/KST4Contest.png" ]; then
             cp "$PKGROOT/usr/lib/KST4Contest/lib/KST4Contest.png" "$PKGROOT/usr/share/icons/hicolor/256x256/apps/KST4Contest.png"
           fi
-          INSTALLED_SIZE=$(du -sb "$PKGROOT" | cut -f1)
-          BUILDDATE=$(date +%s)
-          WORKFLOW_SHA256=$(sha256sum "$GITHUB_WORKSPACE/.github/workflows/nightly-artifacts.yml" | awk '{print $1}')
-          {
-            echo "pkgname = kst4contest"
-            echo "pkgbase = kst4contest"
-            echo "xdata = pkgtype=pkg"
-            echo "pkgver = ${PKGVER}-1"
-            echo "pkgdesc = KST4Contest amateur radio contest logger"
-            echo "url = https://github.com/${{ github.repository }}"
-            echo "builddate = ${BUILDDATE}"
-            echo "packager = GitHub Actions"
-            echo "size = ${INSTALLED_SIZE}"
-            echo "arch = ${ARCH}"
-            echo "license = custom"
-            echo "depend = java-runtime"
-            echo "depend = gst-plugins-base"
-            echo "depend = gst-plugins-good"
-          } > "$PKGROOT/.PKGINFO"
-          {
-            echo "format = 2"
-            echo "pkgname = kst4contest"
-            echo "pkgbase = kst4contest"
-            echo "pkgver = ${PKGVER}-1"
-            echo "pkgarch = ${ARCH}"
-            echo "pkgbuild_sha256sum = ${WORKFLOW_SHA256}"
-            echo "packager = GitHub Actions"
-            echo "builddate = ${BUILDDATE}"
-            echo "builddir = /build"
-            echo "startdir = /build"
-            echo "buildtool = makepkg"
-            echo "buildtoolver = 7.0.0-1-x86_64"
-            echo "buildenv = !distcc !color !ccache check !sign"
-            echo "options = !strip docs libtool staticlibs emptydirs zipman purge !debug !lto"
-          } > "$PKGROOT/.BUILDINFO"
-          tar --zstd --transform 's|^\./||' -cf "dist/${ASSET_BASENAME}-archlinux-${ARCH}.pkg.tar.zst" -C "$PKGROOT" .
+          INSTALLED_SIZE=$(du -sk "$PKGROOT" | cut -f1)
+          cat > "$PKGROOT/.PKGINFO" << EOF
+          pkgname = kst4contest
+          pkgbase = kst4contest
+          pkgver = ${PKGVER}-1
+          pkgdesc = KST4Contest amateur radio contest logger
+          url = https://github.com/${{ github.repository }}
+          builddate = $(date +%s)
+          packager = GitHub Actions
+          size = ${INSTALLED_SIZE}
+          arch = ${ARCH}
+          license = custom
+          depend = java-runtime
+          EOF
+          tar --zstd -cf "dist/${ASSET_BASENAME}-archlinux-${ARCH}.pkg.tar.zst" -C "$PKGROOT" .
 
       - name: Upload Arch Linux artifact
         uses: actions/upload-artifact@v4.3.4
@@ -408,11 +385,11 @@ jobs:
           echo "SHORT_SHA=$SHORT_SHA" >> "$GITHUB_ENV"
           echo "ASSET_BASENAME=KST4Contest-${VERSION}-${SHORT_SHA}" >> "$GITHUB_ENV"
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Ensure mvnw is executable
         run: chmod +x mvnw
@@ -451,18 +428,14 @@ jobs:
           finish-args:
             - --socket=wayland
             - --socket=x11
-            - --socket=pulseaudio
             - --share=network
             - --share=ipc
             - --device=dri
-            - --filesystem=~/.praktiKST
-            - --env=ALSA_CONFIG_PATH=/app/share/alsa/asound.conf
           modules:
             - name: kst4contest
               buildsystem: simple
               build-commands:
-                - install -d /app/lib/KST4Contest /app/bin /app/share/applications /app/share/alsa
-                - printf '@include /usr/share/alsa/alsa.conf\npcm.!default { type pulse }\nctl.!default { type pulse }\n' > /app/share/alsa/asound.conf
+                - install -d /app/lib/KST4Contest /app/bin /app/share/applications
                 - cp -a . /app/lib/KST4Contest/
                 - printf '#!/bin/sh\nexec /app/lib/KST4Contest/bin/KST4Contest "$@"\n' > /app/bin/KST4Contest
                 - chmod 755 /app/bin/KST4Contest
@@ -480,103 +453,18 @@ jobs:
                   path: flatpak-src/KST4Contest
           EOF
 
-      - name: Import Flatpak signing key
-        run: |
-          echo "${{ secrets.FLATPAK_GPG_PRIVATE_KEY }}" | gpg --batch --import
-          FLATPAK_GPG_KEY_ID=$(gpg --list-secret-keys --with-colons | awk -F: '/^fpr/{print $10; exit}')
-          echo "FLATPAK_GPG_KEY_ID=$FLATPAK_GPG_KEY_ID" >> "$GITHUB_ENV"
-
-      - name: Build Flatpak repo (nightly)
+      - name: Build Flatpak bundle
         run: |
           flatpak-builder --force-clean target/flatpak-build target/de.x08.KST4Contest.yml
-          flatpak build-export --gpg-sign="$FLATPAK_GPG_KEY_ID" target/flatpak-repo target/flatpak-build nightly
-          flatpak build-update-repo --gpg-sign="$FLATPAK_GPG_KEY_ID" target/flatpak-repo
+          flatpak build-export target/flatpak-repo target/flatpak-build
+          flatpak build-bundle target/flatpak-repo "dist/${ASSET_BASENAME}-linux-x86_64.flatpak" de.x08.KST4Contest
 
-      - name: Create flatpakref (nightly)
-        run: |
-          REPO_NAME="${GITHUB_REPOSITORY#*/}"
-          PAGES_URL="https://${GITHUB_REPOSITORY_OWNER}.github.io/${REPO_NAME}/"
-          GPG_KEY_B64=$(gpg --export "$FLATPAK_GPG_KEY_ID" | base64 -w 0)
-          cat > "dist/de.x08.KST4Contest.nightly.flatpakref" << EOF
-          [Flatpak Ref]
-          Name=de.x08.KST4Contest
-          Branch=nightly
-          Title=KST4Contest (Nightly) – ON4KST Chat Client
-          Url=${PAGES_URL}
-          RuntimeRepo=https://flathub.org/repo/flathub.flatpakrepo
-          GPGKey=${GPG_KEY_B64}
-          IsRuntime=false
-          EOF
-
-      - name: Upload flatpakref
+      - name: Upload Flatpak artifact
         uses: actions/upload-artifact@v4.3.4
         with:
-          name: flatpakref
-          path: dist/de.x08.KST4Contest.nightly.flatpakref
-
-      - name: Upload Flatpak OSTree repo
-        uses: actions/upload-artifact@v4.3.4
-        with:
-          name: flatpak-ostree-repo
-          path: target/flatpak-repo/
-
-  publish-flatpak-repo:
-    name: Publish Flatpak OSTree Repo (nightly)
-    runs-on: ubuntu-latest
-    needs: build-flatpak
-
-    steps:
-      - name: Install Flatpak tooling
-        run: |
-          sudo apt-get update -qq
-          sudo apt-get install -y --no-install-recommends flatpak
-
-      - name: Import Flatpak signing key
-        run: |
-          echo "${{ secrets.FLATPAK_GPG_PRIVATE_KEY }}" | gpg --batch --import
-          echo "FLATPAK_GPG_KEY_ID=$(gpg --list-secret-keys --with-colons | awk -F: '/^fpr/{print $10; exit}')" >> "$GITHUB_ENV"
-
-      - name: Download OSTree repo artifact
-        uses: actions/download-artifact@v4.1.3
-        with:
-          name: flatpak-ostree-repo
-          path: flatpak-ostree-repo/
-
-      - name: Checkout existing flatpak-repo branch
-        uses: actions/checkout@v4.1.7
-        with:
-          ref: flatpak-repo
-          path: existing-flatpak-repo
-
-      - name: Merge nightly build into flatpak-repo
-        run: |
-          cd existing-flatpak-repo
-          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
-          git config user.name "github-actions[bot]"
-          # Copy the new OSTree build into the repo
-          rsync -a ../flatpak-ostree-repo/ ./
-          # Regenerate summary with all branches
-          flatpak build-update-repo --gpg-sign="$FLATPAK_GPG_KEY_ID" .
-          # Generate .flatpakrepo with embedded GPG key so users can do remote-add without errors
-          REPO_NAME="${GITHUB_REPOSITORY#*/}"
-          PAGES_URL="https://${GITHUB_REPOSITORY_OWNER}.github.io/${REPO_NAME}/"
-          GPG_KEY_B64=$(gpg --export "$FLATPAK_GPG_KEY_ID" | base64 -w 0)
-          cat > kst4contest.flatpakrepo << EOF
-          [Flatpak Repo]
-          Title=KST4Contest
-          Url=${PAGES_URL}
-          Homepage=https://github.com/${GITHUB_REPOSITORY}
-          Comment=KST4Contest – ON4KST Chat Client for VHF/UHF contests
-          GPGKey=${GPG_KEY_B64}
-          EOF
-          # Stage all changes (new/updated refs, summary, objects in OSTree)
-          git add -A
-          if git diff --cached --quiet; then
-            echo "No changes to commit"
-          else
-            git commit -m "Nightly flatpak: $(echo ${{ github.sha }} | cut -c1-7)"
-            git push https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}.git HEAD:flatpak-repo
-          fi
+          name: linux-flatpak
+          path: dist/KST4Contest-*-linux-x86_64.flatpak
+          retention-days: 14
 
   build-macos-dmg:
     name: Build macOS DMG (${{ matrix.os }})
@@ -599,11 +487,11 @@ jobs:
           echo "ASSET_BASENAME=KST4Contest-${VERSION}-${SHORT_SHA}" >> "$GITHUB_ENV"
           echo "ARCH=$ARCH" >> "$GITHUB_ENV"
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Ensure mvnw is executable
         run: chmod +x mvnw
diff --git a/.github/workflows/tagged-release.yml b/.github/workflows/tagged-release.yml
index 929d4d2..7bf4859 100644
--- a/.github/workflows/tagged-release.yml
+++ b/.github/workflows/tagged-release.yml
@@ -22,11 +22,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4.1.7
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Install WiX Toolset
         shell: pwsh
@@ -70,11 +70,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4.1.7
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Ensure mvnw is executable
         run: chmod +x mvnw
@@ -143,11 +143,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4.1.7
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Install packaging dependencies
         run: |
@@ -173,7 +173,6 @@ jobs:
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
             --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec \
-            --linux-package-deps "libgstreamer1.0-0,libgstreamer-plugins-base1.0-0,gstreamer1.0-plugins-good" \
             --dest dist
           DEB="$(ls dist/*.deb | head -n 1)"
           if [ -z "$DEB" ]; then
@@ -195,11 +194,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4.1.7
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Install packaging dependencies
         run: |
@@ -225,7 +224,6 @@ jobs:
             --main-class kst4contest.view.Kst4ContestApplication \
             --module-path target/dist-libs \
             --add-modules javafx.controls,javafx.graphics,javafx.fxml,javafx.web,javafx.media,java.sql,java.net.http,jdk.crypto.ec \
-            --linux-package-deps "gstreamer1,gstreamer1-plugins-base,gstreamer1-plugins-good" \
             --dest dist
           RPM="$(ls dist/*.rpm | head -n 1)"
           if [ -z "$RPM" ]; then
@@ -247,11 +245,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4.1.7
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Install packaging dependencies
         run: |
@@ -306,42 +304,21 @@ jobs:
           if [ -f "$PKGROOT/usr/lib/KST4Contest/lib/KST4Contest.png" ]; then
             cp "$PKGROOT/usr/lib/KST4Contest/lib/KST4Contest.png" "$PKGROOT/usr/share/icons/hicolor/256x256/apps/KST4Contest.png"
           fi
-          INSTALLED_SIZE=$(du -sb "$PKGROOT" | cut -f1)
-          BUILDDATE=$(date +%s)
-          WORKFLOW_SHA256=$(sha256sum "$GITHUB_WORKSPACE/.github/workflows/tagged-release.yml" | awk '{print $1}')
-          {
-            echo "pkgname = kst4contest"
-            echo "pkgbase = kst4contest"
-            echo "xdata = pkgtype=pkg"
-            echo "pkgver = ${PKGVER}-1"
-            echo "pkgdesc = KST4Contest amateur radio contest logger"
-            echo "url = https://github.com/${{ github.repository }}"
-            echo "builddate = ${BUILDDATE}"
-            echo "packager = GitHub Actions"
-            echo "size = ${INSTALLED_SIZE}"
-            echo "arch = ${ARCH}"
-            echo "license = custom"
-            echo "depend = java-runtime"
-            echo "depend = gst-plugins-base"
-            echo "depend = gst-plugins-good"
-          } > "$PKGROOT/.PKGINFO"
-          {
-            echo "format = 2"
-            echo "pkgname = kst4contest"
-            echo "pkgbase = kst4contest"
-            echo "pkgver = ${PKGVER}-1"
-            echo "pkgarch = ${ARCH}"
-            echo "pkgbuild_sha256sum = ${WORKFLOW_SHA256}"
-            echo "packager = GitHub Actions"
-            echo "builddate = ${BUILDDATE}"
-            echo "builddir = /build"
-            echo "startdir = /build"
-            echo "buildtool = makepkg"
-            echo "buildtoolver = 7.0.0-1-x86_64"
-            echo "buildenv = !distcc !color !ccache check !sign"
-            echo "options = !strip docs libtool staticlibs emptydirs zipman purge !debug !lto"
-          } > "$PKGROOT/.BUILDINFO"
-          tar --zstd --transform 's|^\./||' -cf "dist/KST4Contest-${{ github.ref_name }}-archlinux-${ARCH}.pkg.tar.zst" -C "$PKGROOT" .
+          INSTALLED_SIZE=$(du -sk "$PKGROOT" | cut -f1)
+          cat > "$PKGROOT/.PKGINFO" << EOF
+          pkgname = kst4contest
+          pkgbase = kst4contest
+          pkgver = ${PKGVER}-1
+          pkgdesc = KST4Contest amateur radio contest logger
+          url = https://github.com/${{ github.repository }}
+          builddate = $(date +%s)
+          packager = GitHub Actions
+          size = ${INSTALLED_SIZE}
+          arch = ${ARCH}
+          license = custom
+          depend = java-runtime
+          EOF
+          tar --zstd -cf "dist/KST4Contest-${{ github.ref_name }}-archlinux-${ARCH}.pkg.tar.zst" -C "$PKGROOT" .
 
       - name: Upload Arch Linux artifact
         uses: actions/upload-artifact@v4.3.4
@@ -357,11 +334,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4.1.7
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Ensure mvnw is executable
         run: chmod +x mvnw
@@ -400,18 +377,14 @@ jobs:
           finish-args:
             - --socket=wayland
             - --socket=x11
-            - --socket=pulseaudio
             - --share=network
             - --share=ipc
             - --device=dri
-            - --filesystem=~/.praktiKST
-            - --env=ALSA_CONFIG_PATH=/app/share/alsa/asound.conf
           modules:
             - name: kst4contest
               buildsystem: simple
               build-commands:
-                - install -d /app/lib/KST4Contest /app/bin /app/share/applications /app/share/alsa
-                - printf '@include /usr/share/alsa/alsa.conf\npcm.!default { type pulse }\nctl.!default { type pulse }\n' > /app/share/alsa/asound.conf
+                - install -d /app/lib/KST4Contest /app/bin /app/share/applications
                 - cp -a . /app/lib/KST4Contest/
                 - printf '#!/bin/sh\nexec /app/lib/KST4Contest/bin/KST4Contest "$@"\n' > /app/bin/KST4Contest
                 - chmod 755 /app/bin/KST4Contest
@@ -435,18 +408,10 @@ jobs:
           FLATPAK_GPG_KEY_ID=$(gpg --list-secret-keys --with-colons | awk -F: '/^fpr/{print $10; exit}')
           echo "FLATPAK_GPG_KEY_ID=$FLATPAK_GPG_KEY_ID" >> "$GITHUB_ENV"
 
-      - name: Determine OSTree branch
-        run: |
-          if [[ "${{ github.ref_name }}" == beta-* ]]; then
-            echo "OSTREE_BRANCH=beta" >> "$GITHUB_ENV"
-          else
-            echo "OSTREE_BRANCH=stable" >> "$GITHUB_ENV"
-          fi
-
       - name: Build Flatpak repo
         run: |
           flatpak-builder --force-clean target/flatpak-build target/de.x08.KST4Contest.yml
-          flatpak build-export --gpg-sign="$FLATPAK_GPG_KEY_ID" target/flatpak-repo target/flatpak-build "$OSTREE_BRANCH"
+          flatpak build-export --gpg-sign="$FLATPAK_GPG_KEY_ID" target/flatpak-repo target/flatpak-build stable
           flatpak build-update-repo --gpg-sign="$FLATPAK_GPG_KEY_ID" target/flatpak-repo
 
       - name: Create flatpakref
@@ -454,11 +419,11 @@ jobs:
           REPO_NAME="${GITHUB_REPOSITORY#*/}"
           PAGES_URL="https://${GITHUB_REPOSITORY_OWNER}.github.io/${REPO_NAME}/"
           GPG_KEY_B64=$(gpg --export "$FLATPAK_GPG_KEY_ID" | base64 -w 0)
-          cat > "dist/de.x08.KST4Contest.${OSTREE_BRANCH}.flatpakref" << EOF
+          cat > "dist/de.x08.KST4Contest.flatpakref" << EOF
           [Flatpak Ref]
           Name=de.x08.KST4Contest
-          Branch=${OSTREE_BRANCH}
-          Title=KST4Contest (${{ startsWith(github.ref_name, 'beta-') && 'Beta' || 'Release' }}) – ON4KST Chat Client
+          Branch=stable
+          Title=KST4Contest – ON4KST Chat Client
           Url=${PAGES_URL}
           RuntimeRepo=https://flathub.org/repo/flathub.flatpakrepo
           GPGKey=${GPG_KEY_B64}
@@ -469,7 +434,7 @@ jobs:
         uses: actions/upload-artifact@v4.3.4
         with:
           name: flatpakref
-          path: dist/de.x08.KST4Contest.*.flatpakref
+          path: dist/de.x08.KST4Contest.flatpakref
 
       - name: Upload Flatpak OSTree repo
         uses: actions/upload-artifact@v4.3.4
@@ -488,11 +453,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4.1.7
 
-      - name: Set up Java 21
+      - name: Set up Java 17
         uses: actions/setup-java@v4.1.0
         with:
           distribution: temurin
-          java-version: "21"
+          java-version: "17"
 
       - name: Ensure mvnw is executable
         run: chmod +x mvnw
@@ -611,60 +576,32 @@ jobs:
           path: dist/KST4Contest-${{ github.ref_name }}-manual-*.pdf
 
   publish-flatpak-repo:
-    name: Publish Flatpak OSTree Repo (${{ github.ref_name }})
+    name: Publish Flatpak OSTree Repo to GitHub Pages
     runs-on: ubuntu-latest
     needs: build-flatpak
 
     steps:
-      - name: Install Flatpak tooling
-        run: |
-          sudo apt-get update -qq
-          sudo apt-get install -y --no-install-recommends flatpak
-
-      - name: Import Flatpak signing key
-        run: |
-          echo "${{ secrets.FLATPAK_GPG_PRIVATE_KEY }}" | gpg --batch --import
-          echo "FLATPAK_GPG_KEY_ID=$(gpg --list-secret-keys --with-colons | awk -F: '/^fpr/{print $10; exit}')" >> "$GITHUB_ENV"
-
       - name: Download OSTree repo artifact
         uses: actions/download-artifact@v4.1.3
         with:
           name: flatpak-ostree-repo
           path: flatpak-ostree-repo/
 
-      - name: Checkout existing flatpak-repo branch
-        uses: actions/checkout@v4.1.7
+      - name: Download flatpakref
+        uses: actions/download-artifact@v4.1.3
         with:
-          ref: flatpak-repo
-          path: existing-flatpak-repo
+          name: flatpakref
+          path: flatpak-ostree-repo/
 
-      - name: Merge build into flatpak-repo
+      - name: Push to flatpak-repo branch
         run: |
-          cd existing-flatpak-repo
+          cd flatpak-ostree-repo
+          git init
           git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
           git config user.name "github-actions[bot]"
-          rsync -a ../flatpak-ostree-repo/ ./
-          # Regenerate summary with all branches (not just the one just built)
-          flatpak build-update-repo --gpg-sign="$FLATPAK_GPG_KEY_ID" .
-          # Generate .flatpakrepo with embedded GPG key so users can do remote-add without errors
-          REPO_NAME="${GITHUB_REPOSITORY#*/}"
-          PAGES_URL="https://${GITHUB_REPOSITORY_OWNER}.github.io/${REPO_NAME}/"
-          GPG_KEY_B64=$(gpg --export "$FLATPAK_GPG_KEY_ID" | base64 -w 0)
-          cat > kst4contest.flatpakrepo << EOF
-          [Flatpak Repo]
-          Title=KST4Contest
-          Url=${PAGES_URL}
-          Homepage=https://github.com/${GITHUB_REPOSITORY}
-          Comment=KST4Contest – ON4KST Chat Client for VHF/UHF contests
-          GPGKey=${GPG_KEY_B64}
-          EOF
           git add -A
-          if git diff --cached --quiet; then
-            echo "No changes to commit"
-          else
-            git commit -m "Flatpak repo: ${{ github.ref_name }}"
-            git push https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}.git HEAD:flatpak-repo
-          fi
+          git commit -m "Flatpak repo: ${{ github.ref_name }}"
+          git push --force https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}.git HEAD:flatpak-repo
 
   release-tag:
     name: Publish Tagged Release
diff --git a/src/main/java/kst4contest/view/map/MapHtmlResources.java b/src/main/java/kst4contest/view/map/MapHtmlResources.java
index f559276..8b78af3 100644
--- a/src/main/java/kst4contest/view/map/MapHtmlResources.java
+++ b/src/main/java/kst4contest/view/map/MapHtmlResources.java
@@ -32,7 +32,7 @@ public final class MapHtmlResources {
         }
     }
 
-    public static String createStationMapHtml() {
+    public static String createStationMapHtml(int tileProxyPort) {
         String leafletCss = readRequiredResource("/web/leaflet/leaflet.css");
         String leafletJs = readRequiredResource("/web/leaflet/leaflet.js");
 
@@ -217,6 +217,7 @@ public final class MapHtmlResources {
                 <script>
                 """ + leafletJs + """
                 </script>
+                <script>window._kstTileProxyPort=__TILE_PROXY_PORT__;</script>
 
                 <script>
                 
@@ -370,21 +371,13 @@ public final class MapHtmlResources {
 
                             jsLog('Leaflet map initialized');
 
-                            const osmTileLayer = L.tileLayer('https://tile.openstreetmap.org/{z}/{x}/{y}.png', {
-                                maxZoom: 19,
-                                attribution: '&copy; OpenStreetMap contributors'
-                            });
-
-                            osmTileLayer.on('tileload', function (event) {
-                                jsLog('OSM tile loaded');
-                            });
-
-                            osmTileLayer.on('tileerror', function (event) {
-                                const src = event && event.tile ? event.tile.src : 'unknown';
-                                jsError('OSM tile load failed: ' + src);
-                            });
-
-                            osmTileLayer.addTo(map);
+                            L.tileLayer(
+                                'http://127.0.0.1:' + window._kstTileProxyPort + '/tiles/{s}/{z}/{x}/{y}.png',
+                                {
+                                    maxZoom: 18,
+                                    attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a>'
+                                }
+                            ).addTo(map);
 
                             map.createPane('beamPane');
                             map.getPane('beamPane').style.zIndex = 410;
@@ -717,6 +710,6 @@ public final class MapHtmlResources {
                 </script>
                 </body>
                 </html>
-                """;
+                """.replace("__TILE_PROXY_PORT__", String.valueOf(tileProxyPort));
     }
 }
diff --git a/src/main/java/kst4contest/view/map/StationMapView.java b/src/main/java/kst4contest/view/map/StationMapView.java
index d0f988a..82250a7 100644
--- a/src/main/java/kst4contest/view/map/StationMapView.java
+++ b/src/main/java/kst4contest/view/map/StationMapView.java
@@ -18,6 +18,7 @@ import kst4contest.ApplicationConstants;
 import kst4contest.locatorUtils.Location;
 import kst4contest.model.ChatPreferences;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
@@ -48,6 +49,7 @@ public final class StationMapView {
     private final Stage stage = new Stage();
     private final WebView webView = new WebView();
     private final WebEngine webEngine = webView.getEngine();
+    private TileProxyServer tileProxyServer;
 
     private Scene scene;
     private BorderPane rootPane;
@@ -127,6 +129,11 @@ public final class StationMapView {
 
     public StationMapView(ChatPreferences chatPreferences) {
         this.chatPreferences = Objects.requireNonNull(chatPreferences, "chatPreferences");
+        try {
+            tileProxyServer = new TileProxyServer();
+        } catch (IOException e) {
+            System.err.println("[StationMap] tile proxy failed to start: " + e.getMessage());
+        }
         initializeUi();
         initializeWebView();
     }
@@ -627,9 +634,8 @@ public final class StationMapView {
             }
         });
 
-        webEngine.setUserAgent("KST4Contest (+https://hamradioonline.de)");
-
-        webEngine.loadContent(MapHtmlResources.createStationMapHtml());
+        int proxyPort = tileProxyServer != null ? tileProxyServer.getPort() : 0;
+        webEngine.loadContent(MapHtmlResources.createStationMapHtml(proxyPort));
     }
 
     private void requestMapInvalidateSize() {
@@ -1446,4 +1452,4 @@ public final class StationMapView {
 
         return storedSize[1];
     }
-}
\ No newline at end of file
+}