Airlock does not cycle correctly in Multiplayer

In the attached save-file I have build an airlock for our ateroid-base, that behaves wrong when playing online with a friend

The intended behavior:

• cycling of the airlock can be started with any of three buttons (outside base, airlock and inside base
• during the cycle process the button are deactivated to prevent interference
• the inner/outer gate is closed
• the airvent de-/pressurizes the room - this take about 3 seconds
• the outer/inner gate is opened
• the gates are only turned on while opening/closing and turned off immediatly after to prevent interference
• Most of the rooms inside the base have an air connection through ducts and open doors. Only the room with the gravity generator is usually closed and pressurized

When playing alone, or when my friend is far enough away from the airlock it behaves as inteded. However when he is close when the airlock is used (for example standing inside it) it almost always fails to work. The exact behavior however may differ and can be any of these:

• The vent of the airlock de-/pressurizes at an extremely low rate of less than 0.1%/s, so the process doesn't take 3s but several minutes
• When both gates of the airlock are closed both its own vent and all other vents of the station claim non pressurized rooms. Only the gravity generator room is still pressurized and filled. Apparently both airlock gates are considered open for air, but there is no airburst of a decompression
• The gates may appear partially opened but are treated as closed or vice versa
• The outer gate is opened and is indeed leaking air, but the inner vents are not recognizing that the room is not pressurized and continue to vent air into space.

With these symptoms I can only speculate, that the airtightness of the station is falsely synchronized when the gates open/close and the vent of the airlock the falsely believes, that a pressurized room is not pressurized, that a non pressurized room is pressurized or that the single airlock-vent must refill the air of the entire station - explaining the low fill-rate.

Sidequestion:

To ensure that there is alway enough empty room in oxygen-tanks to depressurize the airlock, I connected an oxygen-tank on one end with the vent and the other with a conveyor sorter. When an event controller registers the tank to be filled more than 50% the sorter is deactivated and in the else-case reactiveted.

Is this a viable design to keep the tank from filling over 50% from one side?