Level Completion Achievements Not Unlocking

For whatever reason the last 3 levels of Halo 2 won’t pop an achievement no matter how many times I replay and beat them. The game itself says I’ve completed 15/15 levels but I don’t have any level specific achievements after the level Gravemind. I’m also stuck with other achievements that are still listed as “Done! Unlocking…” after almost 2 days.
Is there any fix to get these level achievements to pop or do I just have to wait it out?