When I get the reciprocal relationship fields they seem sorted by post_date and they no longer follow the admin order.
new WP_Query( array( 'relationship' => array( 'id' => 'posts_to_posts', 'to' => get_the_ID(), ), 'nopaging' => true, ) );
Cross relationship fields works fine. I’m not sure if there are any additional parameters that I need to add to get the administrator order. Thanks!