After upgrading to 14.6.1 books and notes no longer sync to iCloud

In reading of Take Control of
Solving Mac Problems I found a section on clearing caches:

Apart from the special caches just discussed, most of your caches live in one of three places: /Library/Caches, ~/Library/Caches, or ~/Library/Containers/app name/Data/Library/Caches/app name (where app name follows the reverse domain name style I explained in Check Preference Files). Any of these cache files can be deleted safely, because apps regenerate cache files automatically as needed.”

I first tried just clearing the cache for Books, that did not work. I then cleared the cache and rebooted. Books is now working again.

At the suggestion of apple I re-installed 14.6.1 and that failed to fix the issue.