I really want a Templated Control in my UWP app. Just like Custom Control in WPF, not User Control. But I can't make it work with Visual Studio 2022. When I add a new Templated Control to the MainPage - app throws an exception saying

Specified cast is not valid

Can reproduce it very quickly:

1. Create a new UWP project
2. Add a new Templated Control - MyControl.cs. That creates a control with minimal code/XAML that should suffice
3. In the MainPage, add <local:MyControl/> to the root grid
4. Run the app - it fails, saying 'Specified cast is not valid'

How can I fix that?