Fixed KeepLastItemInView Does Not Scroll to Last Item When Adding Items at Top

src/Controls/src/Core/Handlers/Items/ItemsViewHandler.Windows.cs

@@ -149,7 +149,7 @@ void OnItemsVectorChanged(global::Windows.Foundation.Collections.IObservableVect
 			{
 				var lastItem = items[itemsCount - 1];
 				// Adjusts the scroll offset to keep the last item in the list displayed when new items are added.
-				ListViewBase.ScrollIntoView(lastItem);
+				ListViewBase.ScrollIntoView(lastItem, ScrollIntoViewAlignment.Leading);
 			}
 		}
 

src/Controls/tests/TestCases.HostApp/Issues/Issue29207.cs

@@ -0,0 +1,77 @@
+using System.Collections.ObjectModel;
+
+namespace Maui.Controls.Sample.Issues;
+[Issue(IssueTracker.Github, 29207, "KeepLastItemInView Does Not Scroll to Last Item When Adding Items at Top, Instead Scrolls to SecondLast Item", PlatformAffected.UWP)]
+public class Issue29207 : ContentPage
+{
+	Issue29207_ItemsViewModel viewModel;
+
+	public Issue29207()
+	{
+		viewModel = new Issue29207_ItemsViewModel();
+		BindingContext = viewModel;
+
+		CollectionView collectionView = new CollectionView
+		{
+			ItemsSource = viewModel.ItemsSource,
+			ItemsUpdatingScrollMode = ItemsUpdatingScrollMode.KeepLastItemInView,
+			ItemTemplate = new DataTemplate(() =>
+			{
+				var label = new Label
+				{
+					FontSize = 20,
+					Padding = 10
+				};
+				label.SetBinding(Label.TextProperty, ".");
+				return label;
+			})
+		};
+
+		var addButton = new Button
+		{
+			Text = "Add",
+			WidthRequest = 120,
+			AutomationId = "InsertItemButton"
+		};
+		addButton.Clicked += Button_Clicked_1;
+
+		var buttonLayout = new HorizontalStackLayout
+		{
+			Padding = 40,
+			Spacing = 40,
+			Children = { addButton }
+		};
+
+		var grid = new Grid
+		{
+			RowDefinitions =
+			{
+				new RowDefinition { Height = GridLength.Auto },
+				new RowDefinition { Height = GridLength.Star }
+			}
+		};
+
+		grid.Add(buttonLayout, 0, 0);
+		grid.Add(collectionView, 0, 1);
+
+		Content = grid;
+	}
+
+	void Button_Clicked_1(object sender, EventArgs e)
+	{
+		viewModel.ItemsSource.Insert(0, $"NewItem");
+	}
+}
+
+public class Issue29207_ItemsViewModel
+{
+	public ObservableCollection<string> ItemsSource = new ObservableCollection<string>();
+
+	public Issue29207_ItemsViewModel()
+	{
+		for(int i = 0; i < 20; i++)
+		{
+			ItemsSource.Add($"Item {i}");
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue29207.cs

@@ -0,0 +1,24 @@
+#if TEST_FAILS_ON_IOS && TEST_FAILS_ON_CATALYST // CollectionView Fails to Keep Last Item in View on iOS and macOS https://github.com/dotnet/maui/issues/18029
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue29207 : _IssuesUITest
+{
+	public Issue29207(TestDevice testDevice) : base(testDevice)
+	{
+	}
+	public override string Issue => "KeepLastItemInView Does Not Scroll to Last Item When Adding Items at Top, Instead Scrolls to SecondLast Item";
+
+	[Test]
+	[Category(UITestCategories.CollectionView)]
+	public void ScrollToLastItem()
+	{
+		App.WaitForElement("InsertItemButton");
+		App.Tap("InsertItemButton");
+		VerifyScreenshot();
+	}
+}
+#endif