Changes not shown

I have a viewmodel named AllUserViewModel that contains a list of UserViewModels.
The UserViewModel is binded with a UserControl.

This is my MainWindow, foreach user I add a UserControl to a stackpanel container.

public partial class MainWindow : Window
{
    public AllUserViewModel allUserViewModel { get; set; }

    public MainWindow()
    {
        InitializeComponent();
        DwmDropShadow.DropShadowToWindow(this);

        allUserViewModel = new AllUserViewModel();
        this.DataContext = allUserViewModel;

        allUserViewModel.Users.Add(new UserViewModel(new User(1, "Robby", "Bezet")));
        allUserViewModel.Users.Add(new UserViewModel(new User(2, "Erwin", "Bezet")));
        allUserViewModel.Users.Add(new UserViewModel(new User(3, "Kevin", "Bezet")));

        foreach (UserViewModel u in allUserViewModel.Users)
        {
            Container.Children.Add(new UserControlButton(u));
        }

        Container.MouseEnter += new MouseEventHandler(Container_MouseEnter);
    }

    void Container_MouseEnter(object sender, MouseEventArgs e)
    {
        UserViewModel u = allUserViewModel.GetUser(2);
        u.Name = "Laurens";   // Doesn't work
    }
}

To each UserControlButton I pass a UserViewModel

public partial class UserControlButton : UserControl
{
    public UserViewModel userViewModel { get; set; }

    public UserControlButton(UserViewModel u)
    {
        this.InitializeComponent();
        this.DataContext = u;
    }
}

And this is my UserControlButton

<UserControl
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:i="http://schemas.microsoft.com/expression/2010/interactivity" xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions"
xmlns:ee="http://schemas.microsoft.com/expression/2010/effects"
mc:Ignorable="d"
x:Class="UserControlSolution.UserControlButton"
x:Name="UserControl"
Height="50" Background="#FF2F2F2F"
VerticalAlignment = "Top"
Margin="2,0,0,5"
>

    <StackPanel x:Name="UserContainer" Orientation="Vertical" VerticalAlignment="Center" Grid.Column="1" Background="{DynamicResource DarkGrey}">
        <TextBlock x:Name="NameLabel" FontSize="16" Foreground="#FFE5E5E5" Text="{Binding Name}" VerticalAlignment="Top" FontFamily="Segoe UI Semibold" RenderTransformOrigin="0.5,0.5" Margin="0,0,0,2"/>
        <TextBlock x:Name="UserStatusLabel" Text="{Binding UserStatus}" TextWrapping="NoWrap" VerticalAlignment="Top" Foreground="#FFE5E5E5" />
    </StackPanel>

</UserControl>

AllUserViewmodel

public class AllUserViewModel : BaseViewModel
{
    ObservableCollection<UserViewModel> _users;

    public AllUserViewModel()
    {
        Users = new ObservableCollection<UserViewModel>();
    }

    /// <summary>
    /// Observable Collection of Users
    /// Uses INotifyPropertyChange when list changes
    /// </summary>
    public ObservableCollection<UserViewModel> Users
    {
        get { return _users; }
        set
        {
            if (_users != value)
            {
                _users = value;
                NotifyPropertyChanged("Users");
            }
        }
    }

    public void AddUser(User user)
    {
        UserViewModel userViewModel = new UserViewModel(user);
        Users.Add(userViewModel);
    }

    public UserViewModel GetUser(int ID)
    {
        foreach (UserViewModel u in Users)
        {
            if(u.ID == ID)
                return u;
        }

        return null;
    }
}

And UserViewModel

public class UserViewModel : BaseViewModel
{
    readonly User _user;

    public UserViewModel(User user)
    {
        if (user == null)
            throw new ArgumentNullException("User");

        _user = user;
    }

    public string Name
    {
        get { return _user.Name; }
        set
        {
            if (value == _user.Name)
                return;

            _user.Name = value;

            NotifyPropertyChanged("UserName");
        }
    }

    public string UserStatus
    {
        get { return _user.UserStatus; }
        set
        {
            if (value == _user.UserStatus)
                return;

            _user.UserStatus = value;

            NotifyPropertyChanged("UserStatus");
        }
    }

    public int ID
    {
        get { return _user.ID; }
    }
}

The problem is that the 3 users are shown initially, but when I try to change the name on the mouse enter event, the name is not changed although the NotifyPropertyChanged was triggered.