It happens somewhat frequently. The Kobo firmware updates, but Calibre doesn't catch up until its next update.
Customize KoboTouchExtended > Metadata, on device & advanced > Attempt to support newer firmware.
Things
might break if Kobo changes the database structure. I've never had it happen in the six years I've been using it. If it does break, a factory reset and
restoring a backup from Kobo Utilities should work.