function ppd_301_on_placeholder() {
    global $post;

    if ( empty( $post ) || empty( $post->ID ) ) {
        return;
    }

    $template = get_post_meta( $post->ID, "_wp_page_template", true );

    if ( $template === "template-placeholder.php" ) {
        $children = get_children(array(
            'post_parent'    => $post->ID,
            'posts_per_page' => 1,
            'orderby'        => "menu_order",
            'order'          => "ASC"
        ));

        if ( ! empty( $children ) ) {
            $child = reset( $children );
            if ( ! empty( $child->ID ) ) {
                wp_redirect( get_permalink( $child->ID ), 301 );
                exit;
            }
        }
    }
}<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="https://www.cyclpac.com/wp-sitemap-index.xsl" ?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"><sitemap><loc>https://www.cyclpac.com/wp-sitemap-posts-post-1.xml</loc></sitemap><sitemap><loc>https://www.cyclpac.com/wp-sitemap-posts-page-1.xml</loc></sitemap><sitemap><loc>https://www.cyclpac.com/wp-sitemap-taxonomies-category-1.xml</loc></sitemap><sitemap><loc>https://www.cyclpac.com/wp-sitemap-taxonomies-post_tag-1.xml</loc></sitemap></sitemapindex>