I use the archive.php template for author information display.
The page displays the number of posts of the author with the get_the_author_posts(); function.
With Co-Authors Plus enabled, I discovered that the result could be false when the last published post was co-authored : the count seems to be the number of posts of the main author of this last published post.
I didn't see any replacement for this function in the template tags. Am I doing something wrong or is there any workaround ?