Oh it’s definitely a bug IMO. My testing shows that custom views ARE saved correctly for each aircraft, however it seems that whichever aircraft modifies one of the custom views first during a session, “owns” that view for the duration of the session, and ALL aircraft will see the first aircraft’s view and not their own. When the sim is restarted all aircraft see their correct custom views until one aircraft decides to change one of the views which will then “stick” for the duration of the session.
Hope this makes sense, can’t think of any better way to describe it.