This works fine on iOS and Android, by the way.
Anyhoo, my app has a Master Detail setup. Some of the Detail pages have the ability to add items to them, which brings up another page. You enter your info and hit either the nav bar back button to cancel, or a nav bar button to save the information. Now, on iOS and Android, the back button takes the place of the Master button, but you can still swipe to bring the Master into view if you wish. You can then go to another Detail page, and when you once again choose to return to this detail page, the new item screen will still be showing.
On WinPhone, however, the Master button is always visible. When on an input screen, it is still visible. If, instead of cancel/back or save, you press the Master button, the Master view comes up. You can choose another option, but you cannot leave the current input page. The Save button is no longer there, and the back button will go back to the main Windows Phone screen. If you select the same detail page the input page is associated with, the save button will come back, and you can get things back to the way they should be...
But this is bad for a user.
So, is there a way to disable the master button? Or at least, ignore it being pressed? For what it is worth, each Detail page is wrapped in a NavigationPage, and the input page is a simple ContentPage that is shown via the Detail page Navigation.PushAsync(...) method. I've included some pictures to show what I'm talking about...