Another interesting thing is if a user adds themselves to the relationship field with the front end button and then I go to the back end and update the post there by just pressing the update button, the user is counted in the reverse relationship query.
My thought was that the post needs to be updated in the ajax code so I added
update_field('volunteers', $volunteers, $cleanup_id);
wp_update_post( $cleanup_id );
$cleanup_id is passed into the ajax function as the post id. Unfortunately this doesn’t seem to update the post.
