When entering the Puzzle room I often find the pillars empty and the door to the loot room unlocked. If I exit the QA and re enter it, everything is fine.
It doesn't reset properly? Some of our QA have started doing this lately. Not sure what is causing it!
This is not a new thing. I reported this monthes ago. I think the problem is more that it do not start properly up.
I would actually note that nightrisers seem to do this too - of course it's probably unrelated, but when it's just after sunrise, if one goes into the sewers, one might still find nightrisers there. Exiting, and coming back tends to get rid of them all.
How long after the last guy completed the quest did you wait before going in? I've noticed this happen if I've gone in right behind someone who just completed it. Also the door to the treasure room might even be open completely.