There's no easy way to say this, but Halo: Master Chief Collection is still broken.
We're now approaching a full four months of various bugs, including matchmaking not working, groups randomly dropping, and other basic features of multiplayer just flat out not being functional.
Microsoft and 343 Studios have heard about this, and will continue to hear about this, until everything is fixed. Today, though, they at least took some steps to try and give back to a community that is tired of excuses and just want a working game.
For those who played Halo:MCC within the first 30 days of launch, you should be receiving a message in your inbox that will have a free month of Xbox Live code. It's good until June 30th, so you don't have to burn it right away. While this is a small token from the groups that are responsible for arguably the worst launch of 2014, it's at least something.