Yeah, this is an issue but there are already other threads about it.
Wraithlord harbour bug in cooperative
Wraithlord tries to sacrifice my friends minions
https://forum.lastepoch.com/t/wraithlord-tries-to-consume-friends-summons-on-co-op-disabling-it-completely/65742
It’s better to go to an existing topic and Voting on it or at least posting confirmation of the issue rather than creating a whole new one.