Halo: Master Chief Collection is an absolute broken mess
Last weekend, I picked up the Halo Master Chief Collection from the Steam sale with a friend. We wanted to play through Halo 1 again, but it was completely unplayable.
You can’t always join another player’s session.
Occasionally, nothing happens when starting a mission.
On certain missions the game just completely freezes.
At certain points the game locks up leaving you unable to move.
It’s just awful. Don’t buy
Sorry that happened, it plays flawlessly for me and all three friends I’ve done online co-op with on MCC. We played Halo 1 and Halo 2 but mostly H1. The whole campaign too and no issues that you’re describing. I might suggest troubleshooting your networks and game installations before blaming the game itself.