Shell BackgroundColor and TabBarBackgroundColor do not update on iOS 15[Bug]

[Paul2795]

Description

See this link: https://issueexplorer.com/issue/xamarin/Xamarin.Forms/14645

I have the same problem.

After upgrading to iOS 15, applications using the Shell.BackgroundColorProperty or Shell.TabBarBackgroundColorProperty and maybe others will stop working due to changes made to the Appearance class in iOS. More details can be found here: https://developer.apple.com/forums/thread/682420.

Steps to Reproduce

1. Start app with an iOS 15 device or simulator
2. Gaze upon the unstyled nav bar and tab bar

Expected Behavior

Nav bar and tab bar should be styled

Actual Behavior

Both the styling value should be carried over

Basic Information

Version with issue:
Last known good version: iOS 14.5
Platform Target Frameworks:
    iOS: 15+
NuGet Packages: Xamarin.Forms
Affected Devices: iOS

Environment

Show/Hide Visual Studio info

Build Logs

Screenshots

How it should work correctly:
https://user-images.githubusercontent.com/120685/134422750-6f6fefdf-b91f-4383-8697-0dee95970164.png

How this appear with IOS 15
https://user-images.githubusercontent.com/120685/134422755-c155766c-5d20-4099-9f2e-fc0a660e796d.png

Reproduction Link

https://github.com/xamarin/Xamarin.Forms/files/7213851/ShellsBustedInIos15.zip

Workaround

It looks like there could be a way to fix this using UINavigationBar.Appearance, but we will need access to the iOS 15 SDK in order to attempt that.

[AndreasReitberger]

As far as I can see, this is already fixed and will be rolled out with the SR6
#14649

[jsuarezruiz]

The issue have been fixed by #14649

[jsuarezruiz]

A new Service Release will be available next week.

[jsuarezruiz]

Feel free to reopen or open again an issue if have problem. Thanks!