The exosuit dock right next to the exosuit checkpoint receives 1000g of oxygen through my ventilation system and then the oxygen just dissapears. I have two rows of 12 exosuits each and only one has this issue. I watch the oxygen through the ventilation overview flow into the dock, it does the charging animation for a split second and then says there is no oxygen. It is essentially wasting 1000g of oxygen everytime it is pumped to that suit, so approxametely 1/24 of the oxygen being produced by my SPOM is lost. Not a big deal, just annoying.
Place an atmosuit dock next to an atmosuit checkpoint, wait several cycles.