Inline entity reference only creates one node

Hi
I'm having this issue: I have two content types , books and authors
In books content type, I have a inline entity reference, so I can look or add a new author.

Using feeds for books fields, I can map the Author > field_book_author (autores: Title).

And the import runs well, the books are imported, but it only creates one author, and always the last one of the csv file.

Am I missing something ?

Thanks