Sorry, personal life got in the way of answering, seriously though, relatively simple and a little embarrassing that I didn’t do this straight off.
I have two locations for my music, one bing a hard drive embedded in my Nucleus and the other, where I rip my cd’s in a zen mk2.
I disconnected my zen in settings, rebooted Roon and reconnected the zen, bingo.
It worked for me, but I let myself get confused by the ROON message regarding my Internet connection, which I knew was solid but checked that anyway, then posted.
I thought about it further and guessed it had to be simpler, as it had worked only the day before.