Posts_per_page may not be working properly

It seems that when using ES, $wp_query->query_vars['posts_per_page'](inc/post-types/class-post-type-slideshow.php line 142) isn't returning the correct posts_per_page used. It's instead using the site default of 10 (get_option( 'posts_per_page' ));

This is happening at es-wp-query/class-es-wp-query-shoehorn.php in reboot_query_vars() (line 219 currently).

Manually setting $query->query['posts_per_page'] will stop es-wp-query from overwriting the posts_per_page, and this should hopefully be a usable fix until we can look more into why the plugin isn't using the correct number.