If you’ve followed the procedure in the manual, it should work.
Which position have you got the mirror adjustment control set to when you reverse? It needs to be set to position ‘L’ on RHD cars (in any VW I’ve owned with dipping mirror function, I’ve kept the mirror adjustment control permanently set in the ‘L’ position unless I need to use the mirror heating function).
After you’ve reversed, the kerbside mirror should return to the non-dipped position when you either a) switch off the engine or b) drive forward and the car reaches a certain speed - I not sure what that speed is but I think it’s something like 10 mph.
