Supply teleporter input leaks polluted oxygen

Hi,

I use the Supply teleporter input to teleport polluted water (and nothing else) from my secondary asteroid to my starting asteroid.
I noticed that the polluted gas animation was running from time to time but didn't think much of it because I thought it was just a graphic issue and didn't actually emitted polluted oxygen.

After a while, it was clear that it did. There is no debris or loose Pwater anywhere around the building so it is the only possible source of the gas leak.

I don't use any mod and the liquid is brought to the teleporter through a dedicated pipe, so I have no idea what could be causing this issue.

I deactivated auto-repair on the pipe to be able to see if a pipe was breaking at any point, but it doesn't happen and the leak still is going.

Regards

EDIT: After this post, I rose the pressure around the teleporter above 1800g/tile and the offgass doesn't happen anymore so I assume there is somehow liquid sitting inside the building ? 
I also realized I was sending Pincha Peppernuts through the conveyor loader so maybe one of them turned to rot on the rails and is now stuck inside the building.
I don't know how to check if any of these is true though.

Antik Stuff.sav

Player.log Player-prev.log