OK, I FINALLY got the problem fixed! Horray!
I went and de-activated ALL my plugins (I had only 8) and then activated the GP plugin. Added license for update, activated the Library Module is Appearence > GeneratePress; clicked on the library tab and VOILA they were all there.
I guess a general solution for problems with wordpress is, when all else fails, deactivate all plugins and see if you’ve still got the problem.
As a note, another person said they upgrade to gogeek and started getting other errors I was also getting. Deactivating Cloudflare did not fix this problem for me. Another person (found on web) said the ShortPixel Plugin was causing the inability to save to functions.php (which I was also having.) So I deactivated that and still did not solve the “sites not found in library.” So I deactivated them all and the GP problem went away. I still have not determined which particular plugin was causing the problem.