Add Action wp_update_post not Updating WYSWIAG editor

Not really sure why this fixed it, but it did:

function modify_post_content( $content ) {

    $screen =  get_current_screen();
    $post_type = $screen->post_type;
        if ($post_type == 'story'){
        require_once('regex.php');
        $response_array = regex($content);
        $content = $response_array['finalString'];
        }
        return $content;    
    }


add_filter('content_save_pre', 'modify_post_content', 10, 1);