Update #2: Scratch the last update. It may still be an Amazon server issue but I am still experiencing the thumbnails problem. A good number of thumbnails are missing and nothing will bring them to my device except a reset, which then seems to affect a different random batch of thumbnails.
And once, instead of the Kindle Oasis User Manual, it downloaded a "Kindle Solstice User Manual" congratulating me on my purchase of the "Kindle Placeholder." Every reference to the device inside the manual was as "Kindle Placeholder."
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Update: This appears to have been an Amazon server issue (it was occurring with both 3G and wi-fi). After another reset of my Oasis, the device appears to be getting 99% of the thumbnails.
Unfortunately, I'll have to reset the other devices because they appear to not make another attempt at grabbing the thumbnails from the cloud otherwise. Is there a way to easily delete/reset the thumbnail cache?
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I am experiencing a serious problem with cover view thumbnails with this update (5.8.1).
I perform a reset on my Kindle devices when a major version firmware update is released. I noticed that I now am missing a fourth to a third of my cover thumbnails. Also, when I download a new book from the cloud which was showing the thumbnail, the thumbnail often reverts to the generic cover thumbnail.
This isn't on just one device. I have a Kindle Oasis, two Kindle Voyages, two Kindle Paperwhite 3s, and one Kindle Paperwhite 2. I am seeing this behavior on ALL of them.
Resetting the devices again just results in different thumbnails going missing.
Is anybody else seeing this in cover view? Any ideas? Any fixes?