Invisible reCaptcha failed, user cannot send the form again

Hello Nathaniel and thank you for posting.
I understand the problem.
However, I have a question. Is it the anti-spam that failed, or is it something else in the form that fails, and then it says that the anti-spam fails?
Thanks again.

Jeremy, I think you're not having the exact same issue. Maybe something else is failing. Can you please start a separate thread so that we can check on it?

Nathanael, I checked the form, and as you mentioned, the form worked. I'm guessing that the invisible captcha will fail if you reload the page many times.
Personally, I'm against using the Invisible captcha. If you have a module form that appears on all pages, soon you will start getting a popup to select trains or traffic lights directly on page load, for no reason.
If you just include it in a contact form, I'm guessing that it will work, but as expected, it will fail a few times. What I have to suggest (which is not the best solution at all, but the only possible solution with invisible captchas) is to create a language override of the error text, and rephrase it to tell the user to refresh the page. However, if they do so, they will lose all their existing form input.
The text that you would need to override is COM_RAPIDCONTACTEX_FORM_AN_ERROR_OCCURRED. The default value of this text is: "An error occurred. Please complete the captcha again, and try one more time."
I hope this makes sense, as we have almost no control on how the captcha works.

Jeremy, maybe this will work for you too. You can change the WRONG_ANTI_SPAM_ANSWER text, which is generic and make it say what you need to.