Akthi The Final Sting bugged, won't attack me, can't do dmg to it..can't leave arena...

Bug Report ID: #3208077613

Right now, I have the same Problem! Anundr died and Akthi is stuck in the tail.

Screenshot:
https://steamcommunity.com/sharedfiles/filedetails/?id=3623865778

Edit:
1. It happens also during the fight, if Akthi is positioned below a tail segment, while Anundr is burrowing and changing places, but he will eventually be free if Anundr burrows enough
2. Only solution seems to be at the moment: press Esc -> "Respawn at checkpoint"