B2B registration does not work, error message: Security check fail


I've chatted with Majid yesterday to solve this problem, but unfortunately I did not receive a follow up or did not see a created ticket.

When you try to rgister as B2B user you receive an error message, see: https://imgur.com/a/U7pvJ
The registration page is: https://me-mats.com/b2b-registration-page/

After Majid checked the issue the error message now shows at the top of the form instead of the right top of the browser screen. We were thinking it would be a plugin issue.

The B2B registration form is handled by this plugin: WooCommerce Wholesale Lead Capture
When I deactivate the plugin I get this error: https://imgur.com/a/zekst

In the security tab of the plugin configuration I saw some wrong configured Recaptcha keys so I replaced them with good ones. Unfortunately this did not solve the problem.

Thank you in advance for the support.

Kind Regards,