Achievements for Halo CE and Halo 2 not unlocking

Whenever I complete a mission for Halo CE Anniversary and Halo 2 Anniversary I should’ve gotten the achievement saying I completed the mission and I already completed the campaigns for both halo CE and halo 2 but I complete the pillar of autumn and should’ve gotten the achievement Halo: CE complete the pillar of autumn but it’s not unlocking even though I’ve completed it on normal difficulty and the same is happening to halo 2 I’ve completed the campaigns for both halo 1 and 2 but the level achievements aren’t unlocking idk if it will work on easy or legendary difficulty either so could somebody help me?

Im having the same problem man, i cant seem to unlock the legendary anniversary achievement. Is there anyone who can help us