@arc I don't think it's our network problem. This occurs only in coop, if it's our end, this should happen also in versus.
Pretty much all coop games will end when all player have been disconnected one by one. They are not leaving because they disappear when running to objectives.
This problem came in some patch after second beta. You should investigate this.
Another game just had this problem and it was a typo in code that was very hard to find and took a lot of time.
Edit. Today I'm getting lost connection from versus too.
@Arc Update: The current patch is unplayable for me, I get kicked 80% percent of the time, and I haven't been able to complete a single match. This happens in coop and versus. I don't see how this is a network thing my side, this doesn't happen on any other game. I would love to play and give more feedback, but I just can't.
Edit: I should also add that I play with my friend and he also gets kicked, but not always in the same round.