It might be worth checking the mirror memory location?
As I suspect, there are two memory settings on the N/S. The user sets one when in the dipped position and another for driving.
Just thinking, if the two positions where the same you may not see it move much, if at all.
...I’d try setting the console to dipped, along with the control knob to ‘L’, and select reverse. This should activate the dipped position.
Now I’d set the dipped position of the N/S mirror you require, using the joystick. Hopefully when you come out of reverse, the mirror should raise back to the normal driving setting.
Fingers crossed.