Ben Z

I'm also affected by this; same exact behavior. I believe I triggered the bug because some of my party made it through the gate in combat, but not the leader. As a result, I left combat, the party teleported to the wrong side of the gate, then the gate timed out and closed. I suspect it's because the switch becomes useless if ANY character makes it through the door, but the door is only permanently opened if either the whole party, makes it through, the leader makes it through, or some later interaction happens. I also reported a bug via email.