This is a design fault, When the passenger door is opened it hits the mirror and knock it out of position. There are only two positions for the mirror, the sensible one where it is obstructing the door or sticking straight out in front of the truck which would be dangerous in an accident. The problem could easily be fixed by allowing another rest position for the mirror but this would have to be done during manufacture of the mirror bracket. How it got past the designers/ quality control I will never know. The solution at present is to readjust the mirror every time the passenger door is opened .