Fixes Simple Custom Post Order and SearchWP

gistfile1.php

<?php

/**
 * Simple Custom Post Order prevents SearchWP results from showing, this function removes the problematic
 * filters during searches only
 *
 * @param $wp_query
 *
 * @return mixed
 */
function my_custom_post_order_searchwp_fix( $wp_query ) {
    if ( is_search() && class_exists( 'SCPO_Engine' ) ) {
        // unset Simple Page Ordering filters
        if ( ! empty( $GLOBALS['wp_filter'] )
             && isset( $GLOBALS['wp_filter']['pre_get_posts'] )
             && ! empty( $GLOBALS['wp_filter']['pre_get_posts'] ) ) {
                foreach( $GLOBALS['wp_filter']['pre_get_posts'] as $key => $registered_filters ) {
                    foreach( $registered_filters as $registered_filter_key => $registered_filter ) {
                        if ( isset( $registered_filter['function'] )
                             && isset( $registered_filter['function'][0] )
                             && is_object( $registered_filter['function'][0] )
                             && $registered_filter['function'][0] instanceof SCPO_Engine ) {
                                unset( $GLOBALS['wp_filter']['pre_get_posts'][ $key ][ $registered_filter_key ] );
                        }
                    }
                }
        }
    }

    return $wp_query;
}

add_filter( 'pre_get_posts', 'my_custom_post_order_searchwp_fix', 999 );