Rare Replay achievements not showing up

This is by far the strangest issue I've had with anything Xbox related! I'm unable to check my Rare Replay achievements for progress info. When I click to check the game's achievements, it takes a lot longer to load than when I check other games' achievements, and the achievements don't even show! It pops up my stats such as "1300/4000 Gamerscore" and "74/0 Achievements" unlocked. That's not a typo. It actually says, "74/0." However, when I check my achievements for other games I have no problems. I've already tried contacting Xbox Support about it, but the troubleshootings (like 3 different ones) we did didn't fix the problem, so my troubleshooting guide sent me the link to here. Has anyone else encountered this problem, or does anyone know a way to fix this?