Unable to sync "Want to read list" through out all my Apple Device
I have a Mac Studio, MacBook Pro, iPhone and iPad. When I add a book to my Want to Read list on the Mac Studio, it is almost immediately displayed on the Want to Read list on my MacBook Pro. All good -- just what I would expect. However, books added to Want to Read on the Mac Studio or MacBook Pro never appear on my iPad or iPhone Want to Read lists.
Interestingly, books added to Want to Read on the iPad or iPhone DO appear in the Want to Read list on the MacBook and Mac Studio.
iCloud synchronization settings for Books (and everything else) are enabled on all devices.
Doing a synchronization with the iPad connected via cable to the MacBook Pro didn't sync the Want to Read list either.
Any assistance to get all devices synchronizing the Want to Read list would be very much appreciated.
[Re-Titled by Moderator]