I am trying to reach rank 10, which requires that I complete the objective "Master Solo Lost Sectors". I've completed today's master lost sector while solo eight or so times, but it still says 3/5 completed. I beat all the champs and always open the chest, and never have anyone else in my fireteam. Whats happening? Can I only beat one master lost sector solo each week? Is it an error in counting? Pretty frustrating, I just wanna get to Exemplar before the end of the season.