ACT 4 boss Benedictus teleports away GAME BREAKING bug

I defeated ack 4 boss Benedictus, but he was in the process of casting a 1-tap mechanic, which I could avoid, and died. After the respawn, the boss just teleports away, door stays shut. Cannot proceed with the game story.

Here is a video on X/Twitter

https://x.com/Kr3stus/status/2002349145894334566?s=20