Rear air suspension blues

[AV8R4AA]

I rep,aced both rear bags with new Arnott brand bags. They seem to lose height in a couple of days. I also rebuilt my compressor as instructed from this forum. I thought a worn out compressor might be losing pressure.
Not so, I’m still getting sagging overnight. Oddly, it’s dead even. No tilt at all. They both sag at same amount. I did a soak test and found
No leaks. I did not check the fitting on top of the bags. I also did not check each bag for leaks because they are 2 weeks old.

Where do I start on this madness?