In P3Dv4 - Num 5 is set by default to Flight controls (center all) AND Look (reset).
In FSX/FSX-SE/P3Dv3 - Num 5 is set by default to Flight controls (center all), but when I press it, my view switches toi the cockpit door (very strange indeed :-?).

My advise would be to change it to Eyepoint (reset). However, changing it to that, you will remove it from Flight controls (center all), which can come in handy at times (at least it does for me).

If you would rather not do that, then assign a joystick/controller button to Eyepoint (reset), which is what I have done, so I can use the POV Hat to move the view around the cockpit, then press the joystick button to reset it.