Boss is untargetable and can't die

I am figthing The Black Crow boss (the one with the bell) in a corrupted nexus T16 map trying to finish the quest "complete a tier 15+ corrupted nexus" with only 1 revive left.

After some time during the fight, the boss just became untargetable and I can't kill him. He can't kill me either because my energy shield recovers itself faster than his attacks can kill me (I can die only if I remove my gear).

I tried to quit and return to the game, but everytime I re-enter the fight, the bug persists.

I reported the bug using the /bug command, which gave me the reference number 1.129.011.876

Happened to me twice. So frustrating.