That's what I thought as well. I believe resetting to factory settings or a reset populate a new and clean database? If so, I've populated many (I had to sign in again every time) and none of it fixed it.
As for Calibre, I'm not that experienced with it. I think I checked the database? It gave me the following:
Code:
Result of running 'PRAGMA integrity_check' on database on the Kobo device:
ok
Additional information
Upon further trial and error I noticed the following. The reader also saves the reading stats using the following steps.
1. Open the book, read, do your thing
2. Go back to Home
3. Open the another book and close out of it.
4. Open the same book as step 1 and close out of it.
After reboot, the stats collected in step 1 will remain.