Registration activation link not working

[Olaf]

When a user register (Virtuemart form), de emaild activation link trigger an 403 error. Activation is not working.

Tested in a clean installation (after making an temporary workaround in the live site).
Joomla 3.9.24 (no sample data) - tested registration, link does work
Installed VirtueMart 3.8.6 10373 (with sample data) - tested, link 403 error.

What is this error? Do i miss a setting somewhere i cannot find on google and faq?

Also strange, when setting new account activation to none and activating recaptcha (2.0), on the registration form it shows 2 recaptcha. On the live site but also on the very basic test site.
(on the live site i use new account activation to none and disabled the first recaptcha with script.

[jenkinhill]

The activation link solution:  http://forum.virtuemart.net/index.php?topic=146092.msg519513#msg519513

Duplicate recaptcha:http://forum.virtuemart.net/index.php?topic=145841.msg518321#msg518321