Rear air suspension collapse caused by bad front strut?
 

About a month ago, on my 2013 S6, the driver's side rear suspension would drop to the ground intermittently after being parked for a few hours or more. Now it dropping to the ground on both rear wheels when parked for a while. When I open the door, the compressor comes on and the car comes back up to normal height. I have not gotten any suspension error messages and the car keeps its height during driving.

I am trying a new mechanic who specializes in German cars. He says that even though the rear of the car is dropping, the issue is a leak in the front passenger air strut assembly.

I thought that was strange. When the driver's side front air strut failed last year, I got an error message and the car would drop on the wheel that needed to be replaced. Does his assessment make any sense or should I be getting a second opinion on this? Thanks!