Klaven's Tower Rogue quest

I can't use the key (both stolen and killed then looted) from the spiked undead on the chest up in the tower at all. Can't right-click key to use and can't right-click chest to open, keeps telling me it's locked.

Quest link:
https://classicdb.ch/?quest=2359

yes, it is bugged: https://www.warmane.com/bugtracker/report/28040

There isn't much you can do I guess