I have a jailbroken Kindle Oasis with 5.8.7.
I've installed Python and SSH and have got a message as a cover "The ScreenSavers Hack has been successfully installed!".
And since that it is the only cover that I see although I have a lot of different books in Kindle (from Kindle store and other books with covers converted from epub and fb2 to azw2).
I've put the empty file "cover" to listss folder (see printscreen) and have set setting in KUAL / Screen Savers / Screen Savers Behavior / Cover and have restarted the device several times and re-installed both Python and SSH once. Nothing helps. What could be the problem?