I completed the Halo Reach campaign on Legendary with a friend of mine in under 3 hours (the time was 2:57:55). I know that some achievements take time to actually work but I got all my other achievements for par time, difficulty, etc. I don’t know if I got a glitch or the time on the game was wrong, anyone had this issue before?
reset your halo and then load into another reach mission and it should pop. had the same issue
It can take up to 72 hours for achievements to unlock, and etc, etc…
Whenever this happens on any Xbox game, I just hold the power button on my Xbox until it completely shuts off, and then turn it on again after about a minute. This has worked for the last few times this has happened to me.