I was doing the Olde Town Drains dungeon with a friend and when we got to the part where it says "search for Doug in Old Town Drains" we started the battle with the Sanitation Capo immediately and did not go to where it said to go to search for Doug. After the battle finished, we went to where the quest arrow said to go to search for Doug and it triggered the dialog for the monsters, even though they were already gone. Unfortunately, it did not acknowledge that we had already defeated them, but they didn't regenerate, even when we tried leaving the room (not the whole dungeon) and coming back in. Eventually, we gave up and had to start the whole dungeon over. I know this was kind of our fault for not following the quest helper arrow, I thought it was frustrating and I wasn't sure if this is a known problem or not.