My LASO playlist for Halo: Reach reflects 12/12 completed but my achievement has not been unlocked. I started from Winter Contingency to Lone Wolf and got it to 11/12. I went to watch the Noble Actual cutscene and got it to 12/12. Achievement remains locked.
Did your ever get your achievement or no?
I’ve got the same for H3: ODST LASO, and the 3 hour legendary run for Halo Reach (did it in ~2:30). (while i was writing this it poped up whil entering a custom firefight)
The ‘Because It Wasn’t Hard Enough’ achievment remains locked despite having completed the LASO-Playlist with score enabled
Also my multiplayer-wins are locked at 413 wins for four years now…
Other things:
The Lone Wolf related achievement translation (german) displays 5.000.000 points instead of 150.000
The MCC achievements have been buggy since the release of the game and affects all the achievements. Maybe your achievement will pop up the next day, the next month or in 15 months.
Just keep playing 