After checking this script, its not possible that it dump all oxygen. It only interacts with blocks set on "Custom Data" configuration. And it only changes the state of air vents after activating the PB with open or close on run argument.
And if you certain that it was immediately after editing the PB maybe is because of some module you have installed.

Let me simplify. 1. Build pb. 2 load script to pb. 3. All vents on grid immediately dump all oxygen out. It's not about the naming or the custom data I need to edit. I literally placed the script in the ob and before I could do anything else the vents blew out all the oxygen in my tanks.

in one grid with multiple rooms there is allot of vents and doors, and not all doors are doors to outside, is not easy to auto discover what vents and doors belong to a room we are. The way to indentify all important blocks are by naming with special name or indentify them on the "Custom Data"/configuration. In this case you don't need to rename nothing only to make the groups if needed and put them on the configuration(Custom Data)

I didnt even get as far and naming anything. Why bother when every vent suddenly expelled all my oxygen before I could. I litterly buit a pb. Installed script. Vents expelled all oxygen from tanks. Then had weird vent issues and air pockets. Had to grind down all blocks and rebuild plus reload to fix. Didn't even have time to set up the custom data field.

I just tested and I see it working, check more carefull the configuration, The o2 tanks are expeled thru the air vents to a close room, maybe the door you open is not set in DoorsGroupName, when running the pb thru button or sensor, always put argument "open" or "close" followed by "name_of_door_or_group" that is already set on configuration "DoorsGroupName" (custom data)
If you set AutoLock=on you should not be able to open door manualy, make sure the air vent names are in correct location, one is for putting air(AirVentName) the other is to remove to save air(AuxiliarAirVentName).
The just installing is not enought, need to set the custom data properly.

This script is broken. On two different saves when using just installing it to a pb causes ever vent to expell all air from my o2 tanks.

Update done!

Because the auxiliary air vent made only to collect oxygen from the room during depressurization is filling pretty fast the oxygen tanks, soon as I can I will update the script, turning off the air vent connected to oxygen generators until the auxiliary air vent has empty his tanks.