This may explain why some folks have issues with connecting their Kobo to their computer while others don't.
From
https://manual.calibre-ebook.com/faq...-touch-glo-etc
I am getting an error when I try to use calibre with my Kobo Touch/Glo/etc.?
The Kobo has very buggy firmware. Connecting to it has been known to fail at random. Certain combinations of motherboard, USB ports/cables/hubs can exacerbate this tendency to fail. If you are getting an error when connecting to your touch with calibre try the following, each of which has solved the problem for some calibre users.