First Reach now Anniversary?

Hey I was checking on my Halo Anniversary stats and I saw that it’s all gone. It’s like when I lost all my campaign progress after finishing the game on legendary (alone and co-op). I don’t understand why, because last time I checked I had everything on it, but now it says that I never played it at all. What’s the deal… I played on it and found every skull, every terminal, and I got every achievement except two. Can someone tell me if I’m not the only one having this problem.