[Siavahda]

I have a Kindle Paperwhite 10th gen, all software up to date. The ebook in question has been sideloaded from Calibre. It's only this one book!

I read some of it, I put it in a Collection. When my Kindle wakes up from sleep mode, the book is out of the collection and now shows my progress at 0% (although if I open it, it opens to where I was reading). The same thing happens any time I connect my Kindle to Calibre; the ebook hops out of the Collection and declares itself at 0%.

I have tried converting the book into MOBI and AZW3 formats, redownloaded it, deleting it and its sdr files from my Kindle. No dice.

I'm willing to bet it's something about the interaction between this book and my Kindle, rather than something wrong with the ebook file itself (see, redownloading it/converting it to different formats, etc). But I really have no clue what's going on, or how to fix it.

It's only happening with this one book, none of my other files.