Debugger says parameter is nil?

I have this code

   method Window1.Button_Click(sender: System.Object; e: System.Windows.RoutedEventArgs);
      begin
      var x := await MyGetData( 'service1.svc/Data/1' ); 
      end;

   class function Window1.MyGetData(path: String) : Task<String>; 
      begin
      var response := await client.GetAsync( path );
      result := nil;
      end;

The parameter to MyGetData is passed as ‘service1.svc/Data/1’. But when the debugger stops in a breakpoint in the MyGetData method, it says the path is nil. But if I display it with a MessageBox.Show, it is correct.

Thanks, logged as bugs://77470

bugs://77470 got closed with status cannotrepro.