Problems with the Sync3 audio system: fader do not stay where I want it when I restart the car

Hi! Am I the only one with this problem? This is annoying. I have to reset the fader every time I restart the car. I prefer the sound coming mostly from the back but it comes back always in the front even if the screen still indicates that it is still coming from the back. My dealership do not understand it and have no solution. Is it normal? Do any of you had this problem and found a solution? Thanks.