Logged out when loading Map (in coop)

Every second map we open, we get logged out to title screen and this repeats every time we try again. The only solution is to open a new waystone. But we're kinda stuck on t1 because we keep loosing our higher tier waystones.

EDIT: We tried leaving the group after the first map that does open, but we still getting logged out in single player, when opening another Map.