I'm running a small dedicated server with my friends and we are running a custom modpack on 1.21.8 neoforge. Initially, only my friends had this issue with Nature's Compass failing to search on their UI but then, I started experiencing the same issue after a couple days. Each time, the server log shows a success message for the search but the compass needle doesn't move nor does the status and radius in the top left. Both modded and unmodded biomes fail to show up on the screen.

Im experiencing the same bug i think but im running 1.21.10,the problem is only on my server in singleplayer i dont have this problem

i found i was running Ancient Artifacts 2 on my server, after deleting it, the compasses worked fine. perhaps another datapack is making this conflict for you