[baursak]

Please help me.

I have been successfully dealt with Kobo-Calibre cooperation in the last couple of weeks.

- my Calibre is equipped with three plugins:
* KoboTouchExtended
* SmartJect
* Kobo Utilities

- my Kobo has NickelMenu and NickelClock on board, nothing else

- before every Kobo USB connection to PC I 1) launch Calibre and 2) make a Kobo reboot (via NickelMenu)

Now about the bad luck in detail:
- the other day I sent two books to Kobo via Calibre and even started to read them
- but this morning all of a sudden Calibre stopped to see these two books
- at the same time Kobo has them both physically (via USB connection in Windows Explorer) and in its database (title, author, series are shown OK)
- I can open them and continue to read from the place I left them yesterday- multiple plug / unplug cycles didn't cure the situation.

Question 1. What is the reason?
Question 2. How to cure it?
Question 3. How can I avoid this in the future?

I made finally sign out / sign in again to my Kobo acc, but this is in fact almost the same as factory reset, except all the books stay on Kobo: no former reading positions, no links with former Collections...

Maybe it's because of some inaccurate cache somewhere?
Or it could be cured with 'rescan_books_full' command from NickelMenu?
I simply stuck