When you teleport across dimensions using /home, your client visually loses all their exp levels. This can be fixed by manually going to the nether and back. This happens on both dedicated servers and single player worlds.
I only tested with the nether, as I don't have access to the end yet in my playthrough, but I imagine a similar thing happens.

this sounds pretty much like CodedSakura/FabricWarps#2 and can be solved by grabbing https://modrinth.com/mod/FabricCrossDimTPFix

awesome, thanks!