Progression stuck right after last boss fight in act 4

Hi, my game froze during the post-fight animation of the last boss in act4. Now I'm stuck with the quest "Find Tavakai" and when I go back to the location of the last fight, nothing is happening. The NPCs all appear off screen on the minimap too.



The zone won't reset even if I respawn at checkpoint or die to the remaining mobs. The shortcut to reset instance from a waypoint doesn't work (the instance UI doesn't pop, I tried resetting keybinds to defaults and removing all skills from action bar).

Also tried to go back to character select, login, tried to kill the process of the game, tried to kill the process of steam + game and also tried to reboot for good measure.

Nothing works and I'm still stuck and can't progress to interlude.

how can I move forward from there?