Published RAS Console leaves frames marks on a screen while dragging.
It's known issue and we are working on a solution.
There are two options which you can use as workaround.
1. Switch to 'Use RemoteApps if available' in ( RAS Console> Farm> RD Session Host> Required Terminal Server )
2. Enable 'Show contents of window while dragging' on the server side ( Windows Explorer> Right Click on This PC> Properties> Advanced System Settings> System Properties> Visual Effects ) and 'Show contents of window while dragging' in ( Parallels Client> Connection Properties> Experience )