The plot thickens.
After seeing that a few people were able to do a successful Search, I tried again and, lo and behold, the album now shows up as 2nd in the Search results, behind the selection I previously referred to.
W.T.F? I suppose one explanation is that I am going mad (one goes mad the same way one goes bankrupt; slowly at first and then suddenly all at once 
), but I think something more Roon is happening.
Does Roon cache its Search results on their servers? If so, then the fact that several people Searched on the album as a result of my post would explain why I can now find it. That explanation might be a stretch and doesn’t explain why I couldn’t at first find it, but I can think of no other Roon Search reason.
Last night, I tried to add the album to my library. That was approximately 8 hours ago. Even tho Roon return a mesage that it was added, Roon seems to be still trying to accomplish that, with the resulting spinning icon.
Dropping that Roon iOS app and bringing it back up results in a blank screen with the message, ‘This album was not found’…