Halo 4 MCC Achievements

I just completed Halo 4’s campaign solo (MCC) but the achievement for it has not popped up. It says I’ve completed 7/8 missions, but on each individual mission says it’s been completed legendary, but the achievements don’t unlock. Help!

Is there a way to search my service record to see which one I need to do again?

Well this is in the wrong forum section

This should be in the MCC section