Yeah man, I don't know. I'm just going off your symptoms. I just know that one time I had an issue where the vehicle wouldn't raise, and it was because the EAS was so far out of range that the settings just didn't register with the ECU; that's the reasoning behind jacking it up manually, then the sensor readings are withing range and the compressor will take over.
Then, you have to figure out why it happened in the first place. For me, it was the whole bent sensor bracket, but also...one of my airsprings was worn out. That doesn't mean it wouldn't hold air, but it was shot and probably affecting things too. I snapped a swaybar end link, too. All in the same day! I was off-road. It was kind of a miracle that I pulled fuses and crept out of the forest.
After that, I had the shock replaced....the dealer couldn't calibrate it (because it was too far out of range) and I ended up doing an iterative calibration myself with the help of the fine customer support folks at GAP. That was good for a while, but indeed that bent bracket (which went undetected at the time despite the GAP people suggesting I look into that possibility) led to problems a year or so later. New compressor (it was probably due anyway) and then finally after some cross-articulation errors we dug into the EAS and found that the bracket was bent; sorted that out, and it took a calibration with ease. Been good ever since.
A lot of what you read on these message boards comes from two sources:
1. Knowledge of how the system or vehicle is designed or otherwise functions.
2. Just experience of the "that happened to me once" variety.
Both are helpful.