3rd ascendancy quest bugged

I'm at the 3rd ascendancy in act 2 cruel (act 5), and the Ascent to Power quest is permanently stuck at "Search Traitor's Passage". When I kill the guy in Traitor's passage he only drops a white key instead of a green quest key, and the quest never progresses.

I also tried deleting all the white keys but I still can't get the quest to progress. Have also tried redoing the whole Traitor's Passage but can't seem to find anything else.

Is this a bug? Seems like there's a thread on reddit talking about the same issue.

same here