On my car, for the mirror to tilt down, the button has to be selected on Passenger mirror. Otherwise, nothing happens.

Kind of make sense: the button feeds the ground electrical connection to the mirror. If you have not selected it, then there is no electrical return going to the passenger side mirror.

Yves

 

correct, remember the OP and myself had the problem where the mirror would tilt down ok when reverse was selected but it would not return to normal position when you drove forward. My second key worked ok today so maybe it was just "one of those Porsche electrical things".