There's a serious bug where you're on a mission killing enemies or whatever else you may be going on, and then on your screen appears the message "Joining Allies" or "Re-Joining Allies" when your still within the vicinity of your teammates and then after a 5 second countdown your teleported to a random spot. I've experienced this 5 times now, 3 times in the last mission I did. I don't know the name of the mission but it involves the Undying Mind but i'm not 100% sure.