Me and my friend are trying this out and at first it worked. Then we both added the FOV mod and OpenInteriors we could both connect to the server but we couldn’t see each other in the scoreboard.
We do have the mod menu and that worked for some time.
I’ve tried restarting both client and server, I restarted my computer. We both removed the mods from our games but we still can’t see each other. It’s almost like we are in the same server but on different worlds.