Book covers don’t display in Books iOS 13.1.3

I added a couple of new .epub books to my Book Library on my Macbook Air (OS Catalina). The cover art is displayed nicely. When I open the Books app on iPad (iOS 13.1.3), the books are not displaying the same cover. A blank generic cover with the book title only is displayed. These books are stored in iCloud. Why is the correct book cover not displaying in iOS? Other books previously added are displayed properly.