Merge branch '4.6.0' into 4.7.0

Directory.Build.props

@@ -13,7 +13,9 @@
     <Product>Xamarin.Forms</Product>
     <ProduceReferenceAssembly Condition="'$(UsingMicrosoftNETSdk)' == 'True' AND '$(Configuration)' == 'Debug'">True</ProduceReferenceAssembly>
   </PropertyGroup>
-  
+  <PropertyGroup>
+    <GitDefaultBranch>main</GitDefaultBranch>
+  </PropertyGroup>
   <Import Condition="'$(SampleProject)' != 'True'" Project="SourceLink.Build.props" />
   <!-- This target is replaced by GitInfo when restored. Allows Version.targets to rely on it before restore. -->
   <Target Name="GitVersion" />

Xamarin.Forms.Platform.UAP/Platform.cs

@@ -334,6 +334,14 @@ namespace Xamarin.Forms.Platform.UWP
 					else
 					{
 						RemovePage(previousPage);
+
+						if(!modal && _modalBackgroundPage != null)
+						{
+							RemovePage(_modalBackgroundPage);
+							_modalBackgroundPage.Cleanup();
+							_modalBackgroundPage.Parent = null;
+						}
+						
 						_modalBackgroundPage = null;
 					}
 
@@ -673,4 +681,4 @@ namespace Xamarin.Forms.Platform.UWP
 			e.Handled = BackButtonPressed();
 		}
 	}
-}
+}