I have answered you:
“Just a simple flight reset can change the state of some avionics switches, because the game loaded a different .flt file like taxi.flt or runway.flt.”
Apart from that, it does not occur to me that changing to external view and then going back to internal resets a gauge state. It could be caused by any other addon you have that I don’t have (just to say something). What I can tell you is that I don’t usually have anything installed in community except the plane I work with, precisely to avoid these problems.
And regarding to your second question it has been answered by Dean or SilentG37.