Form not redirecting / working when recaptcha shortcode is added

When I add the recaptcha shortcode to the form it doesn’t redirect to the thank you page and the form doesn’t work. #wpcf7-f4-p14-o2 shows up on the contact form page’s url and a 404 ‘page cannot be found’ error is shown.

But when I remove the recaptcha shortcode the form works perfectly, it redirects to the thank you page, sends the form data and it shows up in the Contact Form DB area.

What is causing this and more importantly how can I fix it!

Thanks in advance.