<Button Content="Hello" Command="{Binding HelloCommand}"/> <!-- Works OK --> 
<Button Content="Hello" Command="{Binding HelloCompositeCommand}"/> <!-- Nope :( -->

public class MainWindowViewModel : BindableBase
    {
        public DelegateCommand HelloCommand { get; set; }
        public CompositeCommand HelloCompositeCommand { get; set; }
        
        public MainWindowViewModel()
        {
            HelloCommand = new DelegateCommand(SayHello, CanSayHello) {IsActive = true};

            HelloCompositeCommand = new CompositeCommand(true);
            HelloCompositeCommand.RegisteredCommands.Add(HelloCommand);
        }

        private bool CanSayHello()
        {
            return true;
        }

        private void SayHello()
        {
            Debug.WriteLine("Hi!");
        }
    }