My question for you is 'What are those people doing outside the main room in the first place?' Once all three wings have been cleared, everyone should be in the main room awaiting for the trolls to sprawn and the warden to enter in. If there are people out in the beginning area, than you are doing it wrong and of course the trolls are going to reset as the gate that separates the corridor and the main room is the reset area
Instance certainly isnt buggy IMO, tough Yes, but not buggy
Camaris, Level 105 LM of Elendilmir.