Kicked from vaults before or in chest room

Online private server
Possible bug
PvE-Conflict
US server
PS4

Both me and my clan mate have been kicked from the elder vaults after killing the final boss. Usually when we are in the chest room but today I was kicked before I entered the chest room. We’ve been in the vaults together and only one of us was kicked and we’ve played the vault solo and been kicked. So far this has occurred in the spider vaults and the snake men vault.