Clicking physical back button crashes the app

[Cfun1]

Clicking physical back button crashes the app:

android.runtime.JavaProxyThrowable: System.NullReferenceException: Object reference not set to an instance of an object
at Xamarin.CommunityToolkit.ToolkitPlatform.get_Context () [0x0000f] in <83bd83002ae142b6a5905a0910e93e54>:0
at Xamarin.CommunityToolkit.UI.Views.ImageSourceValidator.IsImageSourceValidAsync (Xamarin.Forms.ImageSource source) [0x00028] in <83bd83002ae142b6a5905a0910e93e54>:0
at Xamarin.CommunityToolkit.UI.Views.AvatarView.OnSourcePropertyChanged (System.Boolean isBindingContextChanged) [0x0030d] in <83bd83002ae142b6a5905a0910e93e54>:0
at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.b__7_0 (System.Object state) [0x00000] in <9435458933084e1282f8b85d1e02e8d9>:0
at Android.App.SyncContext+<>c__DisplayClass2_0.b__0 () [0x00000] in <607c0542851844e698784498ff8ed2d5>:0
at Java.Lang.Thread+RunnableImplementor.Run () [0x00008] in <607c0542851844e698784498ff8ed2d5>:0
at Java.Lang.IRunnableInvoker.n_Run (System.IntPtr jnienv, System.IntPtr native__this) [0x00008] in <607c0542851844e698784498ff8ed2d5>:0
at (wrapper dynamic-method) Android.Runtime.DynamicMethodNameCounter.64(intptr,intptr)

A XamarinCommunityToolkit bug xamarin/XamarinCommunityToolkit#1345.