I have a main page:

MainPage : ContentPage

There are also pages that I navigate to using

await Navigation.PushModalAsync(NewPage);

When I have several pages in my stack and I press the Back button twice, the application freezes and the screen has a white background.

Can someone tell me which way to dig the problem?

I assume that the problem here is related to asynchronous calls, but I do not know where to wait for the shutdown.