Doesn’t work via WordPress registration on wp-login.php

I’ve tested the plugin out for use with one of our clients, but we can’t seem to get this to sync with our Stormpath account if we sign up using the wp-login.php register form. It works if we create a user within the admin area, and it works if we create without Stormpath and login to the site.

But if we enable registrations for WordPress, and try to sign up from the frontend of the site, it doesn’t seem to create the account in Stormpath. Hopefully this makes enough sense ??