They don't tend to go out of adjustment by themselves, but obviously if things have been moved by someone, then it's possible.
If "P" and "1" correlate between the shifter and the dash readout then everything else should.
If this is the case then there should be no blanks on the screen between gears as there should be constant contact.
Having said that, they can still function if there is the occasional tiny loss of contact, without triggering the fault

