My brother and I were playing Reach together to get some of the DLC Achievements and during the time we were playing he completed a challenge, about 30 minutes later both of our xboxs lost internet connection and when he logged back on his challenges were reset. He completed the same one again on accident and it gave him a day Cr ban. TRY TO AVOID REDOING THE BROKEN CHALLENGES AGAIN.
I have the same problem. I were playing halo reach and when I complete the challenge, this one is reset. I don’t know why. Someone do you know?