Shadow Mettle Defeat the guardians bug

Im stuck with my char. In this shadow mettle mission (Shadow lottery).
I was supposed to kill 3 guardians. Killed off one, 2nd guardian activates, take him down to 0 health but he doesnt ”die”. He just shows up at his starting point with 0 health, next to the 3rd guardian. I cant attack it or target it.
Ive tried the unstuck-button. Tried to teleport. I can join dungeon parties etc. But it wont let me teleport.
If i restart game i always come back to this room with same status.
1st guardian defeated
2nd guardian 0 health (bugged)
3rd guardian not active
Pretty frustrating. Please help.