Hello Damien,
I am seeing this error message in the console:
Uncaught (in promise) Error: Missing required parameters: sitekey
at W2.<anonymous> (recaptcha__en.js:82:161)
at new W2 (recaptcha__en.js:549:409)
at RJ.<anonymous> (recaptcha__en.js:280:494)
at new RJ (recaptcha__en.js:723:425)
at recaptcha__en.js:147:466
at (index):689:38
at c4wp_onloadCallback ((index):712:11)
This error seems to have came from the Google Captcha that you are using in your site. Are you using any plugin that has this feature? Please make sure to update all your plugins and test the site again. It would also help if you can do the rest of this troubleshooting:
If nothing is helping, please provide us access so we can check your site settings. You can create a secure note in your next reply with the following info:
– Link to your site
– WP login URL
– WP username
– WP password
– WP Administrator Role
– Confirmation that we can access and make changes to your site
To know how to create a secure note, please check this out: How The Forum Works

Best Regards.