Legend achievement

So July 10th last year i finally beat Halo 2 on Legendary but the Legend achievement never went past 98% even tho beat all on legendary. Have tried replaying levels done about half but still at 98%
Image of when i unlocked the legendary achievements
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ope someone can help me since im currently trying to get to 250K gamerscore and having this finally unlock will help alot

I had just beaten all campaigns on Legendary and have the same issue. Halo CE, 2 and 3 have like 68%, 98%, ect. I believe it has to do with some missions you played offline, so the game didn’t “count” it. I sorta found a fix (well it’d make it easier) just go to your profile on Waypoint, then your service record, and select MCC, then select Halo 2 under campaign completion, and look through the missions on solo and co-op and find whichever one is grayed out with no Par Time or anything, that’s the mission you need to beat to get the completion. And sadly for me I have to do about 9+ missions again across the board, so it sucks. Hope this helps.

i never played missions offline tho. also got a par time on all does weirdly say same time on all halo 2 missions but know all those counted as was already 2% behind friend b4 we started H2