Craiceann, First of the Deep does not phase transition / stay invulnerable in last phase

Bug Report ID: #2470160443

Farming Craiceann, First of the Deep for challenges. I went into the room where the last phase happens (underground, after the water level goes down), and now the boss stays invulnerable. Leaving via portal and rejoining the instance made no difference. I also cannot exit through the door you enter the last part of the arena (which is normal for boss fights).

I could not find a way to continue the fight.

Furthermore, I tried to replicate the bug 11 more times while farming the boss and had no success in replicating it.

One thing I found was, that the boss, when it is underground, gets blocked by my golems (which I have 18 of). Maybe that is part of the problem.