My friend cannot see me

A friend and I are having the problem that I can see them but they can't see me. What we've tried so far (according to [1]):

- /class, one by one or both at the same time for 10 seconds
- /ignore add -> /ignore remove from both sides
- restarting minecraft / relogging

Nonetheless, they couldn't see me for over a month now, without times where it works.

Do you have any idea why this could be? We're both playing on 1.12 with the Wynntils mod installed.

Thanks in advance.

[1] https://forums.wynncraft.com/threads/my-friend-is-invisible.267390/

 

you guys are on the same world yes?

 

yes.

Interestingly, we can see each other if we are not on the same world. this bug only happens if we are on the same world.

 

This is a minecraft bug, not a wynncraft one, and you may need to join a different world with your friend to make it work