Email shortcodes not working in Email

Three of the seven Global Email Shortcodes I included in my email set up did not result in the fields being displayed in the resulting emails sent.

The three are (username), (user_registered) and (user_email)

Please see the attached screenshots of both the email setup screen and received email.

By the way, what is the difference between the two fields (username), (user_registered)? This was what I was trying to find out by inserting them into the email.