Recaptcha v2 valid response not recognized

Recaptcha v2 field response is not recognized on submit (the page reloads and the form data is not saved.)

Reproduction

Specifics

Running a fresh installation of Umbraco 7.12.3 and Umbraco Forms 7.0.5, both installed into an empty project with Nuget. Tested with both IIS and IIS Express

Steps to reproduce

1. Create an empty .NET application, install the latest release of Umbraco and Umbraco Forms via nuget.
2. Add valid API credentials to umbracoForms.config, and add a recaptcha v2 to the sample form.
3. Add the sample form to a page with the Umbraco Forms macro
4. Navigate to the page with the embedded form, fill out any required fields, and complete the recaptcha field.
5. Press submit

Expected result

The form should be submitted and saved when the recaptcha checkbox is checked (and the hidden textarea containing the postback value is present.)

Actual result

A valid captcha response is recognized in the UI (green checkbox), and an apparently valid token is added to the hidden textarea (#g-recaptcha-response). But, the form is not submitted/saved, and the recaptcha field prompts you to revalidate.

[craigs100]

Having similar trouble with Forms 7.0.4 in a 7.12.3 site in that it doesn't have client side validation out of the box. Refers: https://issues.umbraco.org/issue/CON-1552. It needs to integrate into the UF validation schema as that is it's primary purpose. Client wants it in but I may have to tell them its not possible using UF.

[karenlk]

I am having this issue also - just updated to Umbraco 7.12.4 and Umbraco Forms 7.0.5.
I noticed the new Recaptcha 2 field and thought I would give it a try, but the submit button is not clickable with the recaptcha field on the page. I have the google recaptcha keys in the forms config file.
I see no errors in the console.
However when trying to inspect the element, it looks to me like the recaptcha field iframe is on top of the Submit button and so preventing anything from click on it.. I moved the recaptcha field to be the first item in the list, and after doing so, was unable to click on ANY of the form fields (since the iframe was "on top" of them)
So I checked the css, and there is a generic IFRAME style that is making the iframe too large.

So above people might have a similar issue as to why the submit button doesn't work.

[nul800sebastiaan]

@shrthnd Unfortunately I've not been able to reproduce this problem, I installed the default Umbraco starter kit, Forms, added recaptcha to the contact form and everything works just fine. Let me know if you have other steps to replicate.