How to hook to the shipping cost calculator - google captcha is hidden

When adding a google captcha to the commerce_checkout_flow_multistep_default form, the google recaptcha is hidden upon calculating the shipping costs.

The Google Captcha is no longer rendered on the page and it is hidden. This causes the form captcha to be invalidated upon submission and therefore there is a validation error.

I believe that somehow the shipping calculator AJAX Refresh causes this and I don't know how to re-render the captcha upon the shipping calculation because I don't know to which function/event I should hook to re-add the captcha in the form.

Your help is very much appreciated.