Answer by Liyun Zhang - MSFT for Binded property of child context not displaying correctly in dotnet maui

I created a new project to test your code. And I deleted the SelectedItem="{Binding SelectedString}" and Text="{Binding PropertyThatDisplaysCorrectly}" due to I didn't see where did you declare the two properties.

In addition, the second CollectionView's parent control is not a Grid. So I delete the Grid.Row="1".

The ViewModel:

   public class MyViewModel : INotifyPropertyChanged   {        private List<MyObject> _listInViewModel { get; set; }        public MyViewModel()        {        }        public List<MyObject> ListInViewModel        {            get => _listInViewModel;            set            {                _listInViewModel = value;                OnPropertyChanged(nameof(ListInViewModel));            }        }        public event PropertyChangedEventHandler? PropertyChanged;        public void OnPropertyChanged([CallerMemberName] string name = "") =>        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));    }

The xaml:

<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"             x:Class="TestCollectionView.MainPage"><CollectionView ItemsSource="{Binding ListInViewModel}" SelectionMode="None" Margin="0, 10"><CollectionView.ItemsLayout><LinearItemsLayout Orientation="Vertical" /></CollectionView.ItemsLayout><CollectionView.ItemTemplate><DataTemplate><VerticalStackLayout><Label Text="TEST" VerticalOptions="Center" /><CollectionView SelectionMode="Single"  ItemsSource="{Binding StringListFromObjectInList}"><CollectionView.ItemsLayout><LinearItemsLayout Orientation="Horizontal" ItemSpacing="10"/></CollectionView.ItemsLayout><CollectionView.ItemTemplate><DataTemplate x:DataType="x:String"><Border Stroke="DarkGray" Padding="10"><Border.StrokeShape><RoundRectangle CornerRadius="20"/></Border.StrokeShape><Label Text="{Binding}" VerticalOptions="Center" HorizontalOptions="Center" /></Border></DataTemplate></CollectionView.ItemTemplate></CollectionView></VerticalStackLayout></DataTemplate></CollectionView.ItemTemplate></CollectionView></ContentPage>

Initialize the data:

public MainPage(){     InitializeComponent();     var vm = new MyViewModel();     BindingContext = vm;     vm.ListInViewModel = new List<MyObject>();     vm.ListInViewModel.Add(new MyObject() { StringListFromObjectInList = new List<string>() { "111", "222", "333" } });     vm.ListInViewModel.Add(new MyObject() { StringListFromObjectInList = new List<string>() { "111", "222", "333" } });     vm.ListInViewModel.Add(new MyObject() { StringListFromObjectInList = new List<string>() { "111", "222", "333" } });}

And the result:

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