I'm having trouble binding a value to a custom ContentView I made.
My MainPage uses CustomFrameView which is a ContentView .
My CustomFrameView has a string BindableProperty . This works fine when I manually enter a string, but fails when I try to use Binding. And I'm sure the binding should work because it works when used on a Label .
Anyone has an idea on why it does not work?

MainPage.xaml

<StackLayout> 
    <!-- DOES work -->
          <Label Text="{Binding Name}"/>
    <!-- DOES work-->
          <controls:CustomFrameView TestName="Test456"/>
    <!-- DOES NOT work-->
          <controls:CustomFrameView TestName="{Binding Name}"/>
        </StackLayout>

MainPage.xaml.cs

public MainPage()
    {
        InitializeComponent();

        BindingContext = new MainPageViewModel();
    }

MainPageViewModel.cs

public partial class MainPageViewModel : ObservableObject
    {
        [ObservableProperty]
        private string name;
    
        public MainPageViewModel ()
        {
            Name = "Test123";
        }
    }

CustomFrameView.xaml.cs

public partial class CustomFrameView : ContentView
    {
    public string TestName
        {
            get => (string)GetValue(TestNameProperty);
            set => SetValue(TestNameProperty, value);
        }
    
        public static readonly BindableProperty TestNameProperty =
            BindableProperty.Create(
                nameof(TestName),
                typeof(string),
                typeof(CustomFrameView),
                "",
                propertyChanged: SetTestNameProperty);
    
    
        private static void SetTestNameProperty(BindableObject bindable, object oldValue, object newValue)
        {     
            var vm = bindable.BindingContext as CustomFrameViewModel;
            vm.TestName = (string) newValue;
        }
    
        public CustomFrameView()
        {
            InitializeComponent();
            this.BindingContext = new CustomFrameViewModel();
        }
    }

CustomFrameViewModel.cs

public partial class CustomFrameViewModel : ObservableObject
    {
        [ObservableProperty]
        private string testName;
    }