Can someone tell me why these sub 3 hour achieveme

Games Halo: The Master Chief Collection
1

For Halo 3 my total time is 2:52:51 if I calculate best times between single and co-op. In ODST my best times add up to 2:51:16 in just single player.

https://www.halowaypoint.com/en-us/games/halo-the-master-chief-collection/xbox-one/service-records/players/gnome13

2

Your ODST looks good to me, but your Halo 3 does not show single player legendary completion. Usually just starting another mission in the game you are going for under 3-hours will recalculate and pop the achievement (as long as you also have single player legendary completion).

3

> 2535417608334132;2:
> Your ODST looks good to me, but your Halo 3 does not show single player legendary completion. Usually just starting another mission in the game you are going for under 3-hours will recalculate and pop the achievement (as long as you also have single player legendary completion).

Ah, yup I completely missed that on Halo 3.