[anacreon]

It used to work for me with Surface Book, the latest versions of Windows 10 and connecting via the dock, but it was growing more difficult these last days: it often didn't work on the first try, but I often had to try several times, sometimes just unplug/plug, sometimes doing a restart of the PC, though even then the device had the "connect" pop-up on first starting but lost it with the PC password screen.

This morning the connection doesn't work, whatever I try, on the Aura One, H2o or Glo HD, even though the last upgrade on the PC was on 16 October, and on the devices 10 October at the latest (Aura One).
They still load if I connect through the dock (not if I connect direct on the Surface.

I don't understand what could cause it when nothing changed anywhere.

@davidfor: I'm using Calibre portable to facilitate syncing with my old Asus laptop, with its own problems (no sound for one since I'm on Windows 10), but was a boon when a virus killed my old Sony for a while, and I need nowadays to upgrade my Tom-tom, which is not recognized by Surface either, since day 1, dock or not. Is it compatible with Calibre management (never heard of that before)?

EDIT: ok before I asked I should have looked at Calibre before asking questions. It won't be easy anyway, since I have 2536 books on the One today, and use 4.1 Go of the 6.9 available. Also many covers above the 600x800 size limit (the compress images tool doesn't change that).