Sprout Forms Recaptcha js error - everything flagged as spam

I’m using the Google reCAPTCHA plugin with Sprout forms. I’m trying to use an invisible reCAPTCHA badge, but I’m getting a js error on page load:

Unhandled Promise Rejection: TypeError: null is not an object (evaluating 't.addEventListener')

When I have reCAPTCHA enabled, every submission goes to spam with the error ["Google reCAPTCHA can’t be blank."]

If I disable it, the form works fine, but it is overwhelmed with spam.

I’m not using a custom form template (well, I customized some of the html elements, but I didn’t touch any of the actual twig elements).

Full error message is attached.