Regenerating in other dimensions won't update your skin to other players, and they will still see you as the last skin they saw you regenerate into. This is most noticeable with the Tardis mod installed since the Zero Room is very handy for handling regeneration. Also apparently sometimes it screws with the arm size, and resets it back to the way it's set in the launcher? I didn't test this issue much since the solution is simply the other players rejoining the game, but it is still very weird and players leaving the game being required to fix this is very inconvenient.

Forge version is 1.16.5 36.2.20
Regeneration mod version is 36.0.2

if any additional information is required, like the full list of mods I'm using, I can provide it.

fixed, wait for 36.0.3