Google Play Books: Why are my ePub 3 covers not showing?

[CrankyLamb]

I recently converted some of my EPUB 2 e-books into EPUB 3 in Calibre, and adjusted the cover so that it is centered, thanks to the help of this community.

However, I have noticed that when I import some of these e-books to Google Play Books on my Android phone, the cover doesn't appear in the thumbnail.

To be clear, if I open the book, I will see the cover, but it doesn't appear in the thumbnail when I look at my bookshelf, as you can see in the screenshot below.

None of the other ePub Readers I've tried on both Android and iOS have this issue. When I import those same EPUB 3 converted e-books into my iPad, the cover appears correctly in the thumbnail on Apple Books.

How do I fix it?

I can send a copy of my e-book if you want to test it on your devices.

[CrankyLamb]

I posted this thread months ago. Can nobody really help?

[DNSB]

Did you check if your cover image is identified as the cover image in the metadata and manifest?

Looking at the .opf file, you should find in the metadata section and the manifest section, entries for the cover image. In the sample I copied/pasted, the cover metadata was the last item in the metadata block and the first item in the manifest section.

    <meta name="cover" content="cover_jpeg" />
  </metadata>
  <manifest>
    <item id="cover_jpeg" href="Images/cover.jpeg" media-type="image/jpeg" properties="cover-image"/>

Otherwise, I would say that Google Play Books on Android is the issue. Have you tried another Android epub reader?