FOA 4 Green Doors (inside) sometimes open

Does anyone know what triggers the large green doors to open? The set I am referring to are opposite of the red door that leads to the sub-levels. They have a scanner in the ceiling but it does not seem to trigger the doors. However, occasionally when I go there to collect adrenaline from the lower levels; the doors are wide open—which is good because there’s an adrenaline at the back of the room.
Random? I know my buddy has seen them open too. What’s the key?

That door has opened to me only once, during The Hellmouth mission and it contained 3x runners. After completing the mission, i have never been able to open those doors.

Though, what i’m more interested is the double-sided green doors at the bottom of the FOA4. I hear the scanner scanning but it gives the error sound and doors remain closed.

My buddy who tends to be compulsive, and will go to FOA4 to check those doors; has seen them opened several times—however they will also be closed upon returning during the same session. He’ll drop a radio inside when it is open and apply it to his “adrenaline run” circuit—
FOA4 has 14 adrenaline’s (15 if those doors are open).

Sometimes they open, sometimes they don’t. Its been like that for a long time. April-patch made us go for plenty of adrenalin runs there.