Как сделать рабочие кнопки в TabItem-е для добавления/удаления TabItem-ов?

Question

Разбираюсь с WPF, .NET-7. Пытаюсь сделать что-то типа меню с табами, стараюсь реализовать через TabControl, в котором возможно будет динамически добавлять и удалять определённые TabItem-ы. Шаблон итемов сделал, чтобы при добавлении добавлялись кнопки, сейчас пытаюсь через команды их добавлять и удалять, но так работает только с нижними кнопками добавления/удаления, но только не работает удаление, хотя команда срабатывает. В чём проблема и как лучше реализовать данную задачу?

TabModel.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
namespace TestProject
{
public class TabModel: INotifyPropertyChanged
{
    private string title;
public string Title
{
    get { return title; }
    set
    {
        title = value;
        OnPropertyChanged("Title");
    }
}

public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged([CallerMemberName] string prop = "")
{
    if (PropertyChanged != null)
        PropertyChanged(this, new PropertyChangedEventArgs(prop));
}

}
}

ApplicationViewModel.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
namespace TestProject
{
public class ApplicationViewModel : INotifyPropertyChanged
{
    private TabModel selectedTab;
public ObservableCollection<TabModel> Tabs { get; set; }

private RelayCommand addCommand;
public RelayCommand AddCommand
{
    get
    {
        return addCommand ??
          (addCommand = new RelayCommand(obj =>
          {
              MessageBox.Show("add tab");
              TabModel tab = new TabModel{ Title = "New Tab" };
              Tabs.Add(tab);
              SelectedTab = tab;
          }));
    }
}

private RelayCommand removeCommand;
public RelayCommand RemoveCommand
{
    get
    {
        return removeCommand ??
          (removeCommand = new RelayCommand(obj =>
          {
              MessageBox.Show("remove tab");
              TabModel tab = obj as TabModel;
              if (tab != null)
              {
                  Tabs.Remove(tab);
              }
          },
         (obj) => Tabs.Count > 0));
    }
}

public TabModel SelectedTab
{
    get { return selectedTab; }
    set
    {
        selectedTab = value;
        OnPropertyChanged("SelectedTab");
    }
}

public ApplicationViewModel()
{
    Tabs = new ObservableCollection<TabModel>
    {
        new TabModel { Title="Tab 1" },
        new TabModel { Title="Tab 2" },
        new TabModel { Title="Tab 3" },
        new TabModel { Title="Tab 4" }
    };
}

public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged([CallerMemberName] string prop = "")
{
    if (PropertyChanged != null)
        PropertyChanged(this, new PropertyChangedEventArgs(prop));
}

}
}

MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace TestProject
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        DataContext = new ApplicationViewModel();
    }
}

}

RelayCommand.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
namespace TestProject
{
    public class RelayCommand : ICommand
    {
        private Action<object> execute;
        private Func<object, bool> canExecute;
    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    public RelayCommand(Action&lt;object&gt; execute, Func&lt;object, bool&gt; canExecute = null)
    {
        this.execute = execute;
        this.canExecute = canExecute;
    }

    public bool CanExecute(object parameter)
    {
        return this.canExecute == null || this.canExecute(parameter);
    }

    public void Execute(object parameter)
    {
        this.execute(parameter);
    }
}

}

MainWindow.xaml

<Window x:Class="TestProject.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:TestProject"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Window.Resources>
    </Window.Resources>
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>
    &lt;TabControl Grid.Column=&quot;0&quot; SelectedItem=&quot;{Binding SelectedTab}&quot; ItemsSource=&quot;{Binding Tabs}&quot;&gt;
        &lt;TabControl.ItemTemplate&gt;
            &lt;DataTemplate&gt;
                &lt;StackPanel Orientation=&quot;Horizontal&quot;&gt;
                    &lt;TextBlock Text=&quot;{Binding Path=Title}&quot;/&gt;
                    &lt;Button Command=&quot;{Binding AddCommand}&quot; Content=&quot;+&quot;/&gt;
                    &lt;Button Command=&quot;{Binding RemoveCommand}&quot;
                            CommandParameter=&quot;{Binding SelectedTab}&quot;
                            Content=&quot;-&quot;/&gt;
                &lt;/StackPanel&gt;
            &lt;/DataTemplate&gt;
        &lt;/TabControl.ItemTemplate&gt;

    &lt;/TabControl&gt;

    &lt;StackPanel Grid.Row=&quot;1&quot; Orientation=&quot;Horizontal&quot;&gt;
        &lt;Button Command=&quot;{Binding AddCommand}&quot;
                Width=&quot;50&quot;
                Height=&quot;50&quot;&gt;+&lt;/Button&gt;
        &lt;Button Command=&quot;{Binding RemoveCommand}&quot;
                CommandParameter=&quot;{Binding SelectedPhone}&quot;
                Width=&quot;50&quot;
                Height=&quot;50&quot;&gt;-&lt;/Button&gt;
    &lt;/StackPanel&gt;
&lt;/Grid&gt;

</Window>