Roommate and I can't play together [STEAM PC]

Games Halo: The Master Chief Collection
1

I can join up with anyone else. Each time my roommate and I try to play together one of us gets a connection issue and booted to main screen.

We can play any other game together with no issues. Its not poor internet. Im unsure how to fix and its becoming demoralizing.

2

I have the exact same issue with my 2 roomies, would love an answer

3

My family is having the same issue. I was trying to play online with my son, and about every other attempt to start a game one of us would get disconnected.