I got my achievement today, its been glitched for me and still was after the patch. What I ended up doing since i really didnt want to wait for another patch was:
Also want to note i did a factory restore 1st but it didn't pop for me until after I deleted my save file (so the factory reset may not be necessary.)
1) Was completely uninstall the game
2) Had to delete my save file completely (including from the cloud)
3) Re-install base game from store (not from Game APP, as it seem to keep dashboarding when i did from there) weird thing install took me 8 hours on 100/75 connection no idea why but let it go.)
4) Replay the characters and it pop (did them in exhibition)
Really not the way to go unless you want to lose all your progress in game. I was done with every other achievement so I gave it a shot.
Unless your like me and really want that 100% now, I wait for either an in-game patch or a patch from microsoft where you can at least copy your saves to an external device.