Zolin and Zolina boss fight cannot be triggered

I tried to fight them once and got killed after i killed one of them, i respawned and clicked the door behind me and the boss fight cannot be triggered anymore, if i walk up to them and use unearth on them their heads tilt back, they keep on speaking but the fight doesn't want to trigger, i tried to go to the waypoint of the entrance but it changed nothing, respawning at checkpoint also doesn't change anything unfortunately...

I can confirm that it's what happened to me as well.
I killed the sister, who kept fighting even after I took her out, then regardless of what I do, I can't start the fight again.

I am in the same position, was there ever a resolution to this?
I also killed Zolina, and died. Now I cannot trigger the fight.
I have logged out of the game and come back, I have went to another zone and did some fighting, then came back, still no luck.