🙈 ... 😎
You must use a method to run the game without anti cheats.
For Steam you can do this with our launcher that is included with our trainer, or you can run the game from STEAM where it indicates
Play Halo MCC Anti-Cheat Disabled
For Gamepass, you will need to use the .lnk file or follow instructions included with the trainer.
Once you have the game running, you can then use this Trainer to toggle it on where the achievements will fire off.