Disco 2 air suspension

Hi I am new to the forum but not to landrovers I have had them for over 30 years and I am hoping someone can help
I am Having issues with the air suspension on a discovery . The suspension keeps dropping (completely) randomly while I am driving and unable to raise again. If you leave it for a given amount of time (not sure yet for how long) but let's say overnight it raises as it should after starting to the correct height if you press the raise button on the dash it will then raise to the off road height as normal and drops to correct height once you drive it a distance at speed.so everything works correctly.
I have changed the air springs on both sides and left it on both normal drive height and the off road setting for over 48 hours each and it did not fall at all.
I have driven it around for about 200miles since I changed the air springs no issues at all then it did it again. left it in a pull in and got my dad to pick me up and take me back next day started raised drove home (about 10 miles) and is still up 12 hours later but I dare not go out in case it dose it again
Please if any one has any ideas I would be so grateful
Thanks ja
Ps Sorry for the long post
The ride height sensors look fine

Could be ride height sensors, but if both sides are doing it i think that maybe suggests something else. Solenoids would cause one side to go also. Have you plugged it in to check ride height values when its misbehaving? SLABS ecu can be cheap used so may be worth swopping out, but you would need to code it with Nanocom or similar

I was wondering if it could be a faulty air realise valve as I guess it must have something to let out air
both sides seem to go down at the same time a rate but I have not had the chance to look for where the air comes from when it happens as I am driving and have not managed to get out and listen in time

Hi, going on guesses can be quite expensive cos it can be a leak, sensor, valve, wiring issue or ECU, you need a diagnostic tool to set it to coils first then if it doesnt drop again while driving a leak is ruled out then you have to watch the live readings when the symptom occurs. If it's not facelift you can unplug all the connectors in the compressor housing and drive it so to rule out a leak but if it's facelift and you do that the SLS warning will bong your mind out, on non facelifts only the warning lights are coming on but that's about all you can rule out without a dedicated scanner