Solo'd Pit of Heresy and Didn't Get the "Usurper" triumph.
Title. You can even look at my Game Activity and see that I completed it by myself. Took three days cause I ran out of time half way through and had to go to bed to wake up for work. Then I was too busy the next day but I completed it today. I literally played no other game mode in between sessions, I don't think I even went to the Tower. Now I've destroyed all motivation I have for this game and have nothing to show for it. Any assistance on this would be much appreciated, Bungie.