CO2 Valve Stem Drifts Out Slowly

I finally got some evidence indicating why I need to dry-fire a whole bunch of shots in the morning to get CO2 running.

I measure the gap between the bottom of the tophat and the top of the valve in the night before going to sleep. It reads 0.1140″ using a feeler gauge. I also verify that the gun shoots “normal”. The next morning, approximately 6 hours later, I measure the gap again, now it is at 0.1465″ indicating that the valve stem has slowly drifted out overnight. Now my gun shoots like there is no CO2 at all. So I remove the CO2 adapter with 12oz CO2 tank attached, use a little force to push the valve stem in. I can actually feel the valve stem just move in a little bit. Put eveything back to the gun, the gun shoots normal again.

So, the question is – Is this a defect in the valve or is it “normal”? This gun and CO2 adapter package is already the 2nd one I got. The first one had the same problem, so I shipped it back to PA and got the exact same setup from Compasseco. It’s a bit hard to believe that in both cases, the valves are all defected. What do you guys think?