add_filter( 'woocommerce_get_breadcrumb', 'add_shop_to_breadcrumb' );
function add_shop_to_breadcrumb( $crumbs ) {
    if ( is_product_category() ) {
        $shop_page_id = wc_get_page_id( 'shop' );
        if ( $shop_page_id > 0 ) {
            $shop_page_url = get_permalink( $shop_page_id );
            // Shop-Link als zweites Element einfügen
            array_splice( $crumbs, 1, 0, array( array( 'Shop', $shop_page_url ) ) );
        }
    }
    return $crumbs;
}