I’m sorry, my post makes no sense. I thought you were looking for a NUC to run Roon Rock.
Usually the latest version of Roon is the one you want because they are continually solving issues and adding features. Roon does not support rolling back to previous versions.
The latest version of Roon is working very well in my setup, could there be something that needs tweaking in yours? It’s difficult to tell, you didn’t give us much to work with. If you get the chance, give the forum more details about your equipment, your network and your difficulties.