Highlights and notes are not save to my Clipping file

I regularly delete the My Clippings file in my Kindle when it gets too big. Usually a new one appears the next time I make a highlight or a note, containing just that one highlight or note.

However, after the last delete, I am unable to save highlights and notes. When I make one a new My Clippings file is created, but it is empty and it remains so no matter how many highlights or notes I make. The highlights and notes are saved somewhere, since they remain in the book, but they are not logged in the My Clippings file.

I’ve tried deleting it again, but the same thing happens. I’ve also tried restarting the Kindle after and before the new file is created, but it doesn’t help.

What can I do?