Players invisible when sent between servers

Hey! I have a few bungeecord servers which seem to render random players invisible when they get sent to another server on the network. This is completely random and seen differently by different users. User 1 might be able to see user 3 4 and 5 but user 2 might only see user 1 and 4.

Is this a common problem? I see no errors in the console or configs.
Thanks for any replies.