This is what I see when I open the Kindle:
https://bayfiles.com/iba8n3Bfn2/Kindle_2_jpg
Now when I enable only books:
https://bayfiles.com/Tba4n9B2nf/Kindle_4_jpg
You can see that last one ("Gutenberg ...") disappeared along with KUAL.
Now only documents:
https://bayfiles.com/f1a5n6B9n0/Kindle_5_jpg
My clippings is just a .txt, the other two are the offenders.
When trying to open:
https://bayfiles.com/g9a0n8B6n4/Kindle_6_jpg
As for the directory itself, this is what I see:
https://bayfiles.com/e9a8nfB9n9/Kindle_7_png . That's with hidden files and OS files visible. Tree:
https://pastebin.com/xwsmzDNL