Mine does dip down and back to normal position automatically after I start the car. I wondered the exact same question with my X3. During the darker months the xenons turned on automatically and did dip.

Try driving close to a wall, turn off your engine and turn manually on the xenons (assuming here they don't light up). Then start the car and look if you can see the lights go down and back up.

I guess by lowering the lights and re-leveling them when car is started, the system is checking if the leveling system is functional. The lights did dip automatically when the car was started even in my previous car (E46) with manual rotate switch and non-xenon lights.

That is the only thing I can think of. What I still am wondering is what is the automatic headlight range control which to my understanding is not the same as automatic leveling. What does it do and how do you see that functioning...

- p