So I’m working through some achievements and they are just not tracking anymore. I did all 3 Halo 4 playlists and nothing and I was working on the thousand kills for Watchers, Knights, and Crawlers and it’s not updating. I’m playing on PC and purchased the game on the Microsoft Store.
I just recently got Connoisseur almost a month after completing my fourth Halo 2 playlist, I still haven’t luck getting the Mardrigal Debut achievement. So it seems you’ll just have to be patient and hope it randomly drops or they fix the bug causing these problems.