I own Halo MCC but haven't been able to play any Microsoft game for years due to some bug they can't fix (it just repeatedly asks me to log in and never fully logs me in), I have the same issue for games like state of decay 2 through the pc xbox app.
In short if I ever want to play halo I rely on an offline copy that isn't linked to steam, I would be eternally grateful for any upload outside of steam/microsoft.