[android]: ModalContainer Destroy commit allowing state loss

src/Controls/src/Core/Platform/ModalNavigationManager/ModalNavigationManager.Android.cs

@@ -414,10 +414,17 @@ public void Destroy()
 				_rootViewLayoutListener?.Invalidate();
 				_rootViewLayoutListener = null;
 
-				_fragmentManager
-					.BeginTransaction()
-					.Remove(_modalFragment)
-					.Commit();
+				if (_windowMauiContext.Context is not null)
+				{
+					_fragmentManager.RunOrWaitForResume(_windowMauiContext.Context, fm =>
+					{
+						fm
+							.BeginTransaction()
+							.Remove(_modalFragment)
+							.SetReorderingAllowed(true)
+							.Commit();
+					});
+				}
 
 				Modal = null;
 				_windowMauiContext = null;

src/Controls/tests/TestCases.HostApp/Issues/Issue23399.cs

@@ -0,0 +1,50 @@
+namespace Maui.Controls.Sample.Issues
+{
+	[Issue(IssueTracker.Github, 23399, "Closing Modal While App is Backgrounded Fails", PlatformAffected.Android)]
+	public class Issue23399: NavigationPage
+	{
+
+		public Issue23399() : base(new TestPage())
+		{
+		}
+
+		public class TestPage : TestContentPage
+		{
+			protected override void Init()
+			{
+				Content = new VerticalStackLayout()
+				{
+					new Button()
+					{
+						Text = "Open Modal",
+						AutomationId = "OpenModal",
+						Command = new Command(async () =>
+						{
+							await Navigation.PushModalAsync(CreateDestinationPage());
+						})
+					}
+				};
+			}
+
+			ContentPage CreateDestinationPage()
+			{
+				return new ContentPage()
+				{
+					Title = "Test",
+					Content = new VerticalStackLayout()
+					{
+						new Button()
+						{
+							AutomationId = "StartCloseModal",
+							Text = "Close Modal",
+							Command = new Command(()=>
+							{
+								Navigation.PopModalAsync();
+							})
+						}
+					}
+				};
+			}
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue23399.cs

@@ -0,0 +1,38 @@
+#if ANDROID
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue23399(TestDevice device) : _IssuesUITest(device)
+	{
+		public override string Issue => "Closing Modal While App is Backgrounded Fails"; 
+
+		[Test]
+		public void MakingFragmentRelatedChangesWhileAppIsBackgroundedFails()
+		{
+			try
+			{
+				App.WaitForElement("OpenModal");
+				App.Tap("OpenModal");
+				App.WaitForElement("StartCloseModal");
+				App.Tap("StartCloseModal");
+				App.BackgroundApp();
+				App.WaitForNoElement("StartCloseModal");
+				App.ForegroundApp();
+				App.WaitForElement("OpenModal");
+			}
+			catch
+			{
+				SaveUIDiagnosticInfo();
+
+				// Just in case these tests leave the app in an unreliable state
+				App.ResetApp();
+				FixtureSetup();
+				throw;
+			}
+		}
+	}
+}
+#endif