Oasis skirmish Spawn door

Me and my friends were in a group and in a skirmish on oasis waiting for a comp game to start. I’m not quite sure if this is a bug since it had never happened to any of us before, but we walked to the enemy spawn doors to stand in front of them and one of my friends walked into the left spawn door and took a lot of damage quickly and pretty much instantly died. We all followed their example, and all of us died. Our genji dove back and noticed that the other spawn doors didn’t do that, and we were all confused. Could someone maybe elaborate/help?