Unable to progress Kopec Quest in Cruel

Steps:
- Joined a public party in Apex of Filth
- Klicked on teleport to player
- Queen of Filth was killed or maybe killed exactly when I teleported
- I took the the key to the temple of kopec
- Went back to Act 3 town
- Left the party
- Went downstairs to the Temple of Kopec entry. Someone else - probably from the former party - opened the temple of Kopec
- The Key to the temple was removed from my inventory
- The door openened, but I could not enter

Current state after closing the game and logging in again:

Game says I should enter the temple, but I can't. The door to the temple remains open, but I can't click it. I tried porting to another player in the temple, but game says I'm in the wrong quest state.

Update: Redoing the Queen of Filth Fight and properly killing the queen fixes the quest state. So I suppose the actual bug is that the idol can be picked up in a party without taking part in the fight.