I have a keg that was connected @ 15 PSI for 4 days at 75-80F while dry hopping. When connected w/gas, I found no leaks. There is a smidgen less than 5 gallons in the keg.
After a four days, I removed the gas and let it sit for another 2-3 days.
Today, when moving it into the refrigerator, I found it to be depressurized. The pressure release gave nothing.
I've got it back under gas, the lid and out post are soaped. No bubbles ...
Is it possible the beer absorbed the gas? Does this sound plausible for the lack of gas in the headspace (minor headspace)?