I have the same issue, my reader (Kindle paperwhite 5.4.4.2) is charging with anything but not showing as a device. I tried it with 5+ cables (all of them works fine with smartphones and external hdd-s) and 5+ computers.
When I plug it I do not even hear the "new device plugged" sound.
I restarted everything attached and separately.
I did factory reset on the reader attached and separately.
please