Wrong user description showing on Author archive

It seems that the author description that's being shown on the author archive is generated by pulling the author of the first post in the result set. However, if the first post contains co-authors, and the author in question is NOT the primary author of the first post, the description appears wrong.

Using the following filter works around the issue:

function mp_author_description_filter( $description ) {

if ( ( is_author() ) && ( function_exists( 'coauthors_posts_links' ) ) ) {

$a = get_user_by( 'slug', get_query_var( 'author_name' ) );
if ( $a ) {
return $a->description;
}

}

return $description;
}
add_filter( 'get_the_archive_description', 'mp_author_description_filter' );

Start at the get_the_archive_description filter and compare its current author selection with the provided get_user_by and author_name workaround. Reproduce an author archive whose first result has co-authors, then verify the archive displays the requested author's description rather than the primary author's description.

Written by the indexing model from the issue text.