[Richard]

All of the solenoids are closed normally. The travel solenoids only open when the ignition is on, and the HWH is in travel of course.

I didn't necessarily implicate your six pack. If you install the isolator between the six pack and the air bags, you can figure out what is what. The isolator should have a gauge on both sides, and a ball valve in the middle.

Install said device. Air up the coach in travel mode with the valve open. Close the valve. Record gauge pressures on both sides.

Here is how to read the Quija board. If the coach stays up, the gauge on the air bag side stays put, and the gauge on the six pack side drops, then you have a six pack problem. If the coach sags, the air bag gauge drops, and the six pack gauge stays up, then you have a leak in the air bag, tanks, or connections to the tanks.