Try hitting your preset, driving a hundred feet or so and hit it again. Should hit within 1-3psi no problem.
When you are at a stop and change the suspension angles so drastically(by airing out) you bind the components up. Drive a little to unbind the suspension and double tap the preset button again. This will allow you to hit the proper preset. This technique is recommended by Airlift themselves.
The 1-3psi difference is typical and perfectly acceptable of a pressure based system.
If you are still having issues there is a section in the settings that adjusts how hard the system try's to hit the exact psi's requested. I forget specifically what it is called and am too lazy to go look. Default is 5. Try adjusting it lower(2-3) and see if that helps
