Hi. I am having the same problem.
When I go to Community Builder: User Management, the list of users has the email field populated. I can see all of their email addresses. However, when I click on an individual user to edit, the email field goes blank. And then I cannot save without manually re-entering the email.
Interestingly, this is only happening with new users who have signed up during this past year. Older users from years ago maintain the email field when I click on a user.
I checked the database tables for CB and the email field is blank for recent registrants. So where is CB pulling the email from (I assume the Joomla users table) and why won't it save properly into CB?
Thanks!
Chad