Add is_main_query check

This is related to sites that are going to have a lot of posts, but you should add in a $query->is_main_query() check inside of filter_guest_authors(). Right now you’re adding the meta query to every WP_Query request that may be getting made on the author page, including AdSanity.

This isn’t a case of requesting you support AdSanity, just that. you only add your plugin’s meta query to the main query.