Hello,
I have read hundreds of books with Kindle Unlimited on my Samsung Galaxy S8. I often experience multiple paragraphs repeating when I read a book. My comment led the author himself to contact me, which made me realize that the book wasn't at fault, it wasn't loading properly.
The checksum should be run in order to ensure the app is loading correctly. In fact, I know it's the app's fault because when I load the exact same book using the Windows app, the issue never occurs.