It is the door near one of the docking platforms - just enter the building and turn left. I can send a picture if you prefer.
Later, when I login again, I will try to repeat and see how I could do it (without entering the room, of course).
Initially, I thought the door could have been opened by a NPC, but they were all traped in a hole, and there was no other NPC patrolling the area.
It is the door in front of the “Weapon Safety Training Sign”, near Southwest entrance.
I stood there for about 20 minutes, and observed a robot NPC that patrols the area. Eventually, he enters the room by opening the door, but exits it by glitching the glass at the side of the door while it closes. I probably entered the room thinking I opened it while he was just behind me.
Finally, the NPC sometimes manage to get inside the room properly, but falls into a hole and gets traped.