Per the manual
"Automatic Headlight Beam
Adjustment
Vehicles with Litronic headlights feature automatic
headlight beam adjustment.
When the ignition is switched on, the level of the
headlight beam automatically changes in accordance
with the vehicle load.
The level of the headlight beam is automatically
kept constant during acceleration and braking.
Checking operation
1. Switch the low beam on.
2. Switch ignition on.The light beam first dips all the way down and
is then adapted to the vehicle load.
The level of the low beam rises perceptibly
when the high beam is switched on.
If these test items are not met, the headlight beam
adjustment must be checked by an authorized
Porsche dealer."
Try the test before going to the dealer. Hope this help.