Hi Jag Owners
I came out to my car today and the rear was down on tires
as soon as i put key to on position it came up to ride height.
Then took car out for about 40 mins of driving shut car off for about 30 min came back out and car again was resting on tires.
This time I started it and light came on vehicle too low I drove it a bit and the light went off and car came up to correct height.
Didnt hear or see any leaks and when I jacked car up a few days ago i didnt hear any air leaks

 

Has the weather cooled off where you live? That's when a leak usually shows up...