Google ReCaptcha not working on contact form

I have setup V2 - checkbox style Google recaptcha for my client and I cannot get the form plugin to play nice with Google. Every time I test the form I get the following error back “reCAPTCHA bot protection has identified this form submission is problematic”.

Here is my contact form yaml.

title: Contact
cache_enabled: false
form:
    name: contact-form
    action: '/contact#contact'
    fields:
        name:
            label: Name
            placeholder: Name
            type: text
            autofocus: true
            validate:
                required: true
        email:
            label: Email
            placeholder: Email
            type: text
            validate:
                required: true
        subject:
            label: Subject
            placeholder: Subject
            type: text
            validate:
                required: true
        message:
            label: Message
            placeholder: 'What''s on your mind?'
            type: textarea
            rows: 5
            validate:
                required: true
    buttons:
        submit:
            type: submit
            value: Send
    process:
        captcha: true
        reset: true
        email:
            from: '{{ config.plugins.email.from }}'
            to: '{{ config.plugins.email.to }}'
            subject: 'langford-assoc.com: {{ form.value.name|e }} - {{ form.value.subject|e }}'
            body: '{% include ''forms/data.html.twig'' %}'
        save:
            fileprefix: contact-
            dateformat: Ymd-His-u
            extension: txt
            body: '{% include ''forms/data.txt.twig'' %}'
        message: 'Thank you for getting in touch!'

I have already updated grav + form plugin to latest versions, and I have configured the form plugin with the correct site key and secret key.

It is work noting that I have also tried changing the form options from the above to the following with no success either.

captcha:
            recaptcha_secret: 6Le...ldK

Does anyone have Google ReCaptcha V2 - Checkbox working with form plugin? I have tried googling this and am finding lots of conflicting information about how to use recaptcha with Grav forms.