Hi, recently I beat all the halo game on legendary. When I beat it the achievement said I hadn’t completed halo 2 even though it gave me the finale achievement for the mission in legendary. I contaced support for help and they told me to wait 72 hours, 80 hours later I still haven’t received the achievement.
Contact me through this email: zyoshix@gmail.com
Or Xbox Live: JordanIsntLucky
Also proof of completion: - YouTube