Update from 3.6.x to 3.6.5 Profile fields
From Joomla! Documentation
The fields marked as `required` in the Plugin User - Profile are set as Optional in the registration form in frontend.
This pertains only to Joomla! version(s): 3.6.5
What is the cause
The data is not loaded into the form.
How to fix
Modify the components/com_users/models/registration.php file by taking of false on the following line.
$form = $this->getForm(array(), false);
$form = $this->getForm(array());