This has happened to my first and second KFHDXs. I'm sure I might not be the only having this issue so I hope this helps those encountering the same issue. Just thought the Troubleshooting Forum doesn't get as much traffic as this Forum does. And yes uninstalling drivers, re-installing drivers,
using different USB cables, and different PCs, and still getting the same issue in a different way now.
I posted the details in the Kindle Fire HDX 7" & 8.9" Q&A, Help & Troubleshooting
Forum if anyone else is having the same issue or knows a solution. Thank you.
EDIT: The issue was resolved. So any clue on how to delete this post/thread to reduce questions and increase helpful rooting help?