I've been doing Heart of Thorns with a friend and was doing the Mordremoth fight in the Heart and Minds quest. I made it to the third time that you have to jump in the air currents to avoid Mordremoth's attacks and I was shot straight up far enough that it removed me from the fight. We had already been disconnected a couple times and after the air current returned me to outside the instance, I just told my friend to finish it.