If your Nucleus is authorized and working (playing music), then your computer is unauthorized. Of course, the Roon server on your computer is still running (in the background) unless you take steps to shut it down.
Thanks for writing in! Based on your account, it looks like you’re currently running Roon Server on your Mac machine. We don’t see any information about a Nucleus at this moment, are you still running into issues?
You can only have a single server authorized with a single Roon licensee. If you want multiple servers running at the same time, you’ll need an active Roon subscription tied to each server.
If you want to run multiple servers at different times, you are free to do so! Roon might act up a bit since it’s programmed around running on a single machine, generally speaking. That said, there are many who have Roon Server installed on numerous devices and switch between the two.