I can not even pass the connection step with the computer. So, I can not see if it's a driver.
On the other hand, I know that the connection is possible and well recognized if I could manage to push the "Connect" button. During my multiple factory reset, I can connect the device with the computer because it automatically confirms the connection instead of having a manual button to accept. But I can do a factory reset whenever I want to add books.
I made a short video to show what happens. I hope his can help.
https://youtu.be/UhhV0Ckutzo