修改项目模板后，SelectedItem在wpf组合框中不起作用

<Window x:Class="WpfApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <ComboBox Name="myComboBox" SelectedItem="{Binding SelectedItem, Mode=TwoWay}" DisplayMemberPath="Name">
            <ComboBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Name}" />
                </DataTemplate>
            </ComboBox.ItemTemplate>
        </ComboBox>
    </Grid>
</Window>

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows;

namespace WpfApp
{
    public partial class MainWindow : Window
    {
        public ObservableCollection<Item> Items { get; set; }
        public Item SelectedItem { get; set; }

        public MainWindow()
        {
            InitializeComponent();
            DataContext = this;

            Items = new ObservableCollection<Item>
            {
                new Item { Name = "Item1" },
                new Item { Name = "Item2" },
                new Item { Name = "Item3" }
            };
        }
    }

    public class Item : INotifyPropertyChanged
    {
        private string name;
        public string Name
        {
            get { return name; }
            set
            {
                name = value;
                OnPropertyChanged(nameof(Name));
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}