debugging map failure

src/main/java/kst4contest/view/map/MapHtmlResources.java

@@ -370,10 +370,21 @@ public final class MapHtmlResources {
 
                             jsLog('Leaflet map initialized');
 
-                            L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
+                            const osmTileLayer = L.tileLayer('https://tile.openstreetmap.org/{z}/{x}/{y}.png', {
-                                maxZoom: 18,
+                                maxZoom: 19,
-                                attribution: '© OpenStreetMap'
+                                attribution: '© OpenStreetMap contributors'
-                            }).addTo(map);
+                            });
+
+                            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);
 
                             map.createPane('beamPane');
                             map.getPane('beamPane').style.zIndex = 410;

src/main/java/kst4contest/view/map/StationMapView.java

@@ -627,6 +627,8 @@ public final class StationMapView {
             }
         });
 
+        webEngine.setUserAgent("KST4Contest (+https://hamradioonline.de)");
+
         webEngine.loadContent(MapHtmlResources.createStationMapHtml());
     }