Air suspension ride height issues

:banghead: Came out of the store tonite with my 1999 Expedition running and noticed that it seemed to lean to the right. Threw a tape measure on it at home with engine/compressor running and sure enough, 4 different ride heights on all 4 corners. Truck is stock with factory air suspension. Anyone else have this issue and can you point me in the right direction to correct. I am suspecting a blocked or leaking airline "BUT" my compressor does not run all the time, (as in a leaking line) and the heights are all the same when truck is off and lines have bled down. Not sure what to do.:uhoh: