WMS Source looses tiles when zoom level gets too high
Some WMS sources are allergic to too small geographic ranges being selected. In this case every query fails and we always receive an empty image.
One block that caused this problem for me:
["USGS"]
source="wms"
endpoint_url="https://basemap.nationalmap.gov/arcgis/services/USGSImageryOnly/MapServer/WMSServer"
When we zoom in one step further, it doesn't work anymore