I have had several Kindles (first generation Kindle through last year's Kindle Touch) and a first generation Kindle Fire. I am only having this problem on my new Kindle Fire HD.
I have dozens of non-Kindle ebooks. I converted them to mobi format using Calibre and uploaded them to my Amazon Cloud drive. I then had no problem downloading them to my old Kindle Fire. Most of them appeared in the Docs directory of the Kindle Fire, but at least I could find them.
I am having a problem downloading them to my new Kindle Fire HD. When I set up my new Kindle Fire, the books all appeared in the Docs Cloud directory. When I downloaded them they all appeared in the Carousel and some appear in the Docs Devise directory, but most are not listed in either the Docs or Books Device directories. The same thing happened when I tried e-mailing the books to my Kindle Fire HD and uploading them directly from my PC using a USB cable.
The only way that I can find them on the Kindle Fire HD is to scroll back through the Carousel or to go to the Docs directory and do a name search of my Libraries.
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