Fixed inappropriate ellipsis will appear when adding more items in collection view

src/Controls/src/Core/Handlers/Items/iOS/ItemsViewLayout.cs

@@ -108,13 +108,15 @@ internal virtual bool UpdateConstraints(CGSize size)
 		{
 			if (size.IsCloseTo(_currentSize))
 			{
+				// Need to update the constraints when dynamically adding items of different sizes
+				ConstrainTo(_currentSize);
 				return false;
 			}
 
 			ClearCellSizeCache();
 
 			EstimatedItemSize = CGSize.Empty;
-			
+
 			_currentSize = size;
 
 			var newSize = new CGSize(Math.Floor(size.Width), Math.Floor(size.Height));

src/Controls/tests/TestCases.HostApp/Issues/Issue26936.xaml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue26936"
+             xmlns:local="clr-namespace:Maui.Controls.Sample.Issues"
+             Title="Issue26936">
+    <VerticalStackLayout>
+        <Button Text="Add new items"
+                AutomationId="Button"
+                Clicked="Button_Clicked"/>
+        <CollectionView x:Name="collectionView"
+                        HeightRequest="50">
+            <CollectionView.ItemsLayout>
+                <LinearItemsLayout Orientation="Horizontal"/>
+            </CollectionView.ItemsLayout>
+        </CollectionView>
+    </VerticalStackLayout>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue26936.xaml.cs

@@ -0,0 +1,30 @@
+using System.Collections.ObjectModel;
+
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 26936, "CollectionView items appear with ellipses or dots when dynamically adding more items.", PlatformAffected.macOS | PlatformAffected.iOS)]
+public partial class Issue26936 : ContentPage
+{
+	Issue26936ViewModel _viewModel = new Issue26936ViewModel();
+
+	public Issue26936()
+	{
+		InitializeComponent();
+		collectionView.ItemsSource = _viewModel.Items;
+		this.BindingContext = _viewModel;
+	}
+	private void Button_Clicked(object sender, EventArgs e)
+	{
+		_viewModel.Items.Add("item: " + this._viewModel.Items.Count);
+	}
+}
+
+public class Issue26936ViewModel
+{
+	public ObservableCollection<string> Items { get; set; }
+	public Issue26936ViewModel()
+	{
+		Items = new ObservableCollection<string>();
+		Items.Add("item: " + "0");
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue26936.cs

@@ -0,0 +1,23 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue26936(TestDevice testDevice) : _IssuesUITest(testDevice)
+{
+    public override string Issue => "CollectionView items appear with ellipses or dots when dynamically adding more items.";
+
+    [Test]
+    [Category(UITestCategories.CollectionView)]
+    public void ShouldCollectionViewEachItemsAppearWithoutDots()
+    {
+        App.WaitForElement("Label");
+        for (int i = 0; i < 50; i++)
+        {
+            App.Tap("Button");
+        }
+
+        VerifyScreenshot();
+    }
+}