The Puzzler quest in the Last Keep seems to be bugged (or possibly some kind of server lag issue).
I took the quest and the pillars were not interactable and the reset switch did nothing. I could walk into the next room to get my reward but I could not turn in the quest for XP/Gold completion and had to abandon the quest.
That happens if you go in too quickly from accepting it. Heading out and back in tends to fix it.