Plugin reCaptcha for WooCommerce adds extra verification.
please, use following code to disable in Phone Orders
add_filter('wpo_before_create_customer', function($data) { global $i13_woo_recpatcha; remove_action('woocommerce_register_post', array($i13_woo_recpatcha, 'i13_woocomm_validate_signup_captcha')); return $data; }); add_filter('wpo_after_create_customer', function($data) { global $i13_woo_recpatcha; add_action('woocommerce_register_post', array($i13_woo_recpatcha, 'i13_woocomm_validate_signup_captcha'), 10, 3); return $data; });