The NavigationPage.IsNavigationBarTranslucent platform-specific on iOS no longer works when consuming it from XAML. However, when consuming it through C# it works correctly.
Repo: run the sample at https://developer.xamarin.com/samples/xamarin-forms/UserInterface/PlatformSpecifics/
Expected result: As per the screenshot in the doc link: https://developer.xamarin.com/guides/xamarin-forms/platform-features/platform-specifics/consuming/ios/#Making_the_Navigation_Bar_Translucent
Actual result: (1) the button isn't shown, (2) the background colour of the navigation bar isn't set to blue.
I've also tried it in 2.3.5-pre6 and the result is the same.
Note: Setting BarBackgroundColor in XAML does set the background color of the navigation bar, but the platform-specific appears to only work on the BackgroundColor property (confirmed from the C# version of the page).
Thanks David, I can confirm that issue.
To view the issue, edit App.xaml.cs to run:
MainPage = new iOSNavigationPage();
instead of the initial MainPage.
To clarify the issue, the background color of the NavigationPage doesn't appear to be set. You can see the navigation bar shift opacity.