Crashing in Multiplayer ONLY when team members are off screen.

I have been playing for over 150 hours no issue until last week. Me and a friend have tested this. As long as we enter the level and stay near each other I will not crash but as soon as they interact with anything (damage enemies or usable objects) a certain distance away (always off screen) I will crash with no error messages. (they are not crashing)

Is anyone else experiencing this? If you are have you found a workaround?
I'd rather not play solo. I like gaming with friends.