So I've been attempting to get the Rat King for a while and hadn't been able to due to lack of friends being on when I would try to get it. But yesterday, I completed the nightfall twice with over 5 minutes remaining, and both of my friends had their rat king in a primary weapon slot not in the vault, and I had the quest still active. Well, when we beat the nightfall both times, I didn't get the completed check on it to be able to get the weapon. I'm not sure why. Any help would be appreciated. Thanks