Student account problem

For my computer science principle course, I encountered a problem with log in issues.
His name is Remen. In my account, I can see his login name: [Remen Ulinfun] Username: remen572
However under his account setting, his login name is: coder_ray3546
When I administrate a quiz, he could not access his assessment online at code.org.

What should I do?
thanks

@li.wang Please contact support at support@code.org.