CF7 fails using Recaptcha integration

Hi Takayuki

I’m a big CF7 fan, but I’ve come across an odd problem. Having just upgraded a small client site to the latest versions of WP and CF7 forms using reCAPTCHA won’t send and give a spam error (orange box).

It is not running Askimet, and I’ve disabled caching for testing as per your FAQ.

On the page linked you’ll see 2 CF7 forms. These are identical except that the one on the right is using reCAPTCHA. I created this simply by duplicating the original form.

Other than that they are identical. reCAPTCHA integration is correct, so I don’t understand it.

Versions:
Wordpress v 4.9.4
CF7 v5.0

Thanks for your help,

Andy

The page I need help with: [log in to see the link]