Just beat the Halo 2 Legendary playlist. None of the 4 achievements for “Complete every level of Halo 2 in…” unlocked. I couldn’t have skulls turned on, so that can’t be a problem. The Halo 2 campaign menu is telling me everything is completed on legendary solo. All 4 of the achievements are at 92% completion.
Just beat Gravemind and now the achievements unlocked. I changed my appearance to offline in the middle of that mission and the terminal glitched out on it. One of those things must of glitched the achievements for that legendary run.