Apple Books quality Issue - skipping pages or pages are blank

I recently downloaded one book and all the pages were black and blank except for a small unidentifiable (so teeny) graphic on every page. So I downloaded another book and it is skipping pages, sometimes whole chapters. I found I could read about 6 lines at a time if I keep my finger on the screen (iPhone 16 Pro iOS 18.2.1). Doesn't always work. I am dumbfounded. Have turn phone off and on, deleted app and reinstated it. Any other ideas?