The Quest "Through a Glass, Darkly" is once again uncompletable

The Quest “Through a Glass, Darkly” is once again bugged.

On the final stage when you are supposed to defeat Thyrinar, he simply casts two spells and drops to the floor like a stone like on my linked image here.

He never returns up, and will consistently do it try, after try, after try. I also tried redoing the entire thing with a reset instance, but nothing helped.

This makes the legendary staff unobtainable currently, as you need to complete this quest.

imgur dot com/a/5pZ5AbM

We have had some reports of this but generally abandoning/retaking the quest and going through the scenario slowly is the way to go.
If you continue seeing this happen, please do make an in-game bug report.

I did bug report it, as retaking the quest, re-doing the scenario, doing it in different speeds does nothing, it still bugs on the same exact spot which means the pre-patch has done something funky to the scenario.
I’m currently doing it on a non max level character, which lacks the damage to kill the dragon instantly before the bug happens.

As you would be able to do the quest at max level by simply one shotting the dragon before it falls to the ground with the bug, but I’m not interested in doing it at max level. Please fix your scenarios so people at appropriate levels can do them.