Why is the bound context not updating?

Question

WPF

I have a context-bound textbox

<TextBox Text="{Binding Path=LeftTeam.TeamCounter, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"  />

If I try to update the context when creating a con, then everything is fine

public View _view = new View();
public MainWindow()
{
            InitializeComponent();
            DataContext = _view;
            _view.LeftTeam.TeamCounter = 7;//изменения видно
}

But when I try to do it later (button click event), the text doesn't change anymore

private void LeftTeamMinusOneCount(object sender, RoutedEventArgs e)
{
            _view.LeftTeam.TeamCounter = 9;//изменения НЕ видно
}

Through the debugger, you can see that the code is being executed and changes in the model are taking place. But the TextBox itself does not display the updated data