[Bug] UWP: PopAsync causes a crash when called from a CollectionView.SelectionChanged event

[JogyBlack]

Description

In latest releases of Xamarin.Forms, calling Navigation.PopAsync() from a CollectionView.SelectionChanged handler causes a crash in UWP projects.
Same code works fine with Android.

Steps to Reproduce

1. Create a simple Xamarin.Forms navigation application with two pages.
2. The main page contains a button to navigate to the second page.
3. The second page contains a CollectionView with several elements, and a SelectionChanged handler. In the SelectionChanged handler call Navigation.PopAsync to return to the main page.

Expected Behavior

The user is navigated back to the main page.

Actual Behavior

Unhandled exception: "Object reference not set to an instance of an object."
at Xamarin.Forms.Platform.UWP.SelectableItemsViewRenderer1.UpdateFormsSingleSelection() at Xamarin.Forms.Platform.UWP.SelectableItemsViewRenderer1.UpdateFormsSelection()
at Xamarin.Forms.Platform.UWP.SelectableItemsViewRenderer`1.NativeSelectionChanged(Object sender, SelectionChangedEventArgs args)

Basic Information

• Version with issue: 4.6.0.967
• Last known good version: 4.4.0.991864
• IDE: Visual Studio 2019
• Platform Target Frameworks:
  • UWP: 16299
• Affected Devices: Windows Desktop

Reproduction Link

Sample project to demonstrate the problem:
App1.zip

Workaround

Instead of handling SelectionChanged, use a TapGestureRecognizer for the items in the CollectionView and call PopAsync() there.

[JogyBlack]

Note: still happens with the just released Xamarin.Forms 4.7.0.968

[mattleibow]

Just tried this with 4.8.0.1364 and it just happened.