Have a look at this thread and see if anything rings a bell:
https://www.mobileread.com/forums/sho...d.php?t=219901
I seriously reduced the incidence of disconnects by doing some housekeeping !
It's always following the "Update metadata" phase where mine bombs out - the books get copied over (sometimes quite large numbers of them) and on disconnect are readable.
Another way that seems reasonably stable is not to load the Kobo drivers but to connect to the Glo as a USB Folder device. I don't think I have ever had a disconnect when running in that mode. This approach is more practical now that jgoguen has produced a Kepub conversion plugin.
BobC