I got the game yesterday and have been playing the campaign a lot with a friend.

However today, half or more of our games disconnected after we finished the mission. We couldn't reconnect, and after going back to the title screen and selecting our characters again, it was as if we never went on the last mission in the first place. Sometimes after being disconnected one of us would be forced to join some other mission we hadn't seen before, either solo or with other people.

Additionally, random people would join our games, and it seemed like if someone joined our game, it was more likely that we would be disconnected at the end of the mission.

Please fix this problem, we replayed so many missions 3 or 4 times in order to pass them. Getting to the end of a mission and having to do it all again is extremely frustrating.