I was making a hydrogen heat exchanger room for an air purifier when I noticed that I was losing pressure in the room.
The hydrogen room is in the space biome, so I thought I may be missing a drywall or tempshift plate tile. I double checked that they are all still there, and I changed the arrangement of the tiles to see if that made a difference, no dice..
Saved and reloaded, and it was fine after.
Map is created in sandbox mode with spaced out DLC. Debugger has been used on the save, but was not open during the construction of this room. Debugger was used to fill the room with hydrogen. The rest of the rooms in the space biome did not see unexpected changes in pressure.
Have Spaced Out DLC enabled.
Create sandbox world, no sweat difficulty.
Turn debugger on and off a few times. Use it to copy and paste a few things.
Create room in space biome using sandbox mode. Make sure room has tempshift plates and drywall tiles behind it.
Use debug mode to fill the room full of hydrogen.
Hope the problem surfaces. Save file is attached.