I had this same issue and I think I’ve found a fix.
Even when not selected, the reCAPTCHA will show up on the WooCommerce checkout page if you have Registraion Form selected. The issue is on line 45 of the anr-captcha-class.php file in the wp-content>plugins>advanced-nocaptcha-recaptcha directory.
The line of code is as follows:
add_action (‘woocommerce_checkout_after_order_review’, array($this, ‘wc_form_field’) );
If you comment that out the reCAPTCHA will only appear if you select WooCommerce Checkout in the plugin settings.
I hope this helps and hopefully this is fixed in a future update!