Kiter

Problem of air suspension. Height adjustment works OK. I set Comfort car is rising, but it is hard, rigid. What could it be? No sport.

mishar

It can be many things. From brake switch, steering angle sensor, ABS module and so on. You need VCDS scan in order to nerrow it.

Mister Bally

There is a pneumatic dampener (shock absorber) in each strut. Although rare, they sometimes fail in a rigid/stuck mode. I've had this happen with a long-gone VW Scirocco which, of course did not have an air system to raise & lower the vehicle. My experience with this was only on bitter cold (-10°F) mornings.

Incaico

So I think this is a related question:

What is the best setting that causes the least stress on the suspension? Automatic, Dynamic or Comfort?

MP4.2+6.0

Logically Comfort since it does the least moving up and down and buffers the ride and hits more than the others when car is dropped lower. But driving like an old lady would reduce it too. I don't own a D3 or W12 to worry I might wear something out and thus get timid. If I did I might as well buy a Prius or something.

mishar

As MP said Comfort. Automatic won't be different since you may very rarely hit 80 mph (?) for long enough to switch it to Dynamic. If you want to make it last even longer you may use VCDS and raise her for 20 mm. She will look a bit like a crossover but ride will be smooth and struts will last longer. Just like you have softer springs. Like old Cadillac.