Auto-vent won't stay open

[Tantalus]

I bought a few of the auto-vents from the station that are supposed to automatically close whenever they detect dangerously low oxygen pressure on one side. Most of the installed vents are working as advertised, however, I have one that refuses to stay open no matter what. I installed it in one of the tiny little vent alcoves across a door. The atmosphere on both sides of the door is fine (a little chilly on one side, but the auto-vent refuses to stay open. As soon as I open it, it immediately closes again. Reinstalling the vent did not help. Has anybody else encountered this?

Note for dev: a control panel override to make the auto-vent function like a regular vent would be nice for situations where you need the vent open to reoxygenate a room.

EDIT: I'm an idiot; the vent wasn't powered. It was merely power-adjacent.

[Randombandit]

They open when there is a difference, not a huge difference. If you don't have an O2 source on the other side it stays unbalanced until you leave a door open.
If you have only one problematic vent, install a normal one next to if and close it. You get the safety function, but can open the standard one when the auto acts up.
And I agree there there should be a lock-open.