My group was doing the raid on hard and when we got to the templar 2 people had to leave so we went back to orbit to get some ammo, when we found 2 new players we went back to orbit but we were sudenly at Atheon, we did switch fireteam leaders but it was another player that was with us so he should have had the gatekeeper checkpoint. I just wanted to share this problem so bungie can see it and maybe fix it before more people are gonna have the same problem.