What i did / Steps to reproduce

Open the map, zoom in and move around

Expected result

No voids forming up

Actual result

A void follows you wherever you move across the map, you can see the terrain in the edges

Context

BlueMap Version:
5.5 Neoforge 1.21.1

• Server is running linux
• The world is a replica of an earth map, 1:750 ratio

Make sure you follow the "Upgrading from xx" notes in the Changelog when updating to a new version.
In your case you likely forgot to update your webapp by deleting the <webroot>/index.html when updating bluemap.

To fix:

• delete your <webroot>/index.html (most likely: ./bluemap/web/index.html)
• reload bluemap

Did that, didn't fix it

Since this is most likely a setup issue and not a bug, can we please switch to our support-discord? :)
GitHub Issues are a bad place to debug this and help you, thanks!