Suspension Bags

Hi
I recently got a Disco 2 facelift model and love it to bits.
The suspension sits fine and the compressor is rarely on which has to be a good sign?
The issue I have is that when the car has been sat and I load the boot with all my music gear for my band, the back drops, when i start the car after so many seconds it lifts again.
If I then leave it loaded and turn off over night the suspension stays up with no issue. I arrive at reherasal and it stays up and i unload no issue, end of the evening I load and it goes down?
Does the SLS shut off after the ignition has been off for a while?
Is this normal?
Advice appreciated.
Regards Ade

That's exactly what it's supposed to do. Although usually if you unload the back it will drop a bit (you can usually hear the air escaping). This is intentional to keep the right height. Mine is quite sensitive - even unloading a bag of shopping makes it drop slightly.

The compressor only works when ignition is on and all doors shut; air release stays on for a while after switching off.

Excellent and also as you have described, many thanks.
Ade