Air suspension failure?

I have a 2008 bmw x5 previous owner said the back driver side air bag is out and it leaned to one side when I got there it was setting normal and drive it home with it being bumpy after a couple of days I drove it and parked it for a couple of hours and it was hanging to the driver side I opened the door and the compressor came on for a little while filled up the passenger side and turned off the passenger side is staying filled but the compressor is not turning on could it be detecting that the driver side air spring is bad and not be turning on because of it or could it be the level sensor or the compressor itself

I have the air springs ordered I I’m just curious to see if there’s anything else that I would need to replace