Thank you very much. It is again the click unauthorize option that I had missed (instead of going back to sign up as suggested). All sorted out except for finding my Roon ready device seemingly not fully certified (yet was working fine until reinstall)
Thanks Nuwriy. The device is La Rosita. The manufacturer is the one who introduced me to Roon (I would never have researched Roon otherwise) and encouraged my taking the lifetime subscription. Worked fabulous with Roon and never had any issue with it. It seems the Big Sur reinstall can no longer enable La Rosita. Although the disclaimer is that the device may not function properly (which is not true), there is no help provided in trying to enable back.