DisplayAlert() in OnDisappearing not working on iOS

Hi!

This is a simplification, but here goes: I have put a DisplayAlert() in my page's OnDisappearing method; on Android it is shown OK after the page disappears but on iOS it is not shown. I'm using Xamarin.Forms 1.3.1.6296.

Anybody knows why it's not shown on iOS?!?

Thanks!
/Nikolaj

Example source code

public class MyPage : ContentPage {
    protected override void OnDisappearing() {
        DisplayAlert("Title", "Message", "OK");
        base.OnDisappearing();
    }
}