Unfortunately the overwritten note could not be recovered.
The error occurred to me exactly this way:
Example: I have the CITIES NOTE and the CHARACTERS NOTE.
I use the search function (Ctrl+K) and use the name of a city.
The search tells me that the CHARACTERS NOTE contains the searched word, and when I click on the result, I see the CHARACTERS NOTE, but with the content of the CITIES NOTE. If I edit the note, this information is automatically overwritten and I lose the total original content of the CHARACTER NOTE.