I noticed that since updating to iBooks using iCloud with iOS 9.3, I'm starting to see this "blank screen" page when staring iBooks. The books are still there, searchable by name or visible when tapping the top left icon.
Toggling between list/shelf view makes books visible on the shelf view again, but this is rather annoying.
How can I make sure my iBooks works properly with iOS 9.3 and iCloud?