What i did / Steps to reproduce

Zoom in to any given point on the map

Expected result

High Res layer should appear

Actual result

black "box" or layer appears

Context

BlueMap Version: BlueMap-5.2-fabric-1.20

See screenshot:

This is not a bug, but an issue with your setup.
Make sure you followed the update-instructions on the release when updating from an older version to 5.2.
Please use our Discord for support with this :)

For anyone else encountering this, I also had to delete the website data on the devices. Only after that, did the map work properly.