I have beat Halo 2 legendary under 3 hours. My service record shows this and in game stats show this, but it has yet to unlock. It’s been many days since I finally beat gravemind, but it still won’t unlock. Any advice on how to fix this?
Try going to last check point and start playing again and beat the level again. It should pop up.
I just redid uprising and finished it a few seconds quicker, but it still has yet to unlock. I already finished halo 3 and halo ce under 3 hours and those two unlocked without an issue.
To any one else having this issue, I have read that in order to get the achievement to unlock for coop players, Halo 2 solo legendary must be complete regardless of time. I am currently running through halo 2 legendary solo and will confirm later if this method works.