It appeared to be reported by someone else. I have to go back to the old version as it is really annoying.
The symptoms are:
Multiple same notebook names - both english and chinese names
It is not sure when it was duplicated - randomly
When select specific one duplicated name, all the same name were selected
All the notes in the duplicated notebooks are exactly same
The duplicated notebooks are essentially one notebook, as I cannot use them individually - e.g. when I change the the name, all the same name changes; When I delete one, all the same name disappear
A temp fix for the issue is: uninstall, delete the database completely and reinstall. However, a few days use the duplicated names come back again!
By the way, I am not sure it is a "language" related issue or not.