Dell Migrate completed, but the user folder name is incorrect

I have a new Dell XPS 17 9720 with Windows 11 Pro installed.   I completed Dell Migrate from my old pc with windows 10 home, which noted some uncopied files, specifically onedrive files. 

In C:\users\ there are now *two* user folders - one with the user name associated with the microsoft account (like the old pc), but then the other used the email address for the user folder name.  Except for onedrive files, all the other data is in the folder with the email name.  When I connect to onedrive it uses the folder with the "correct" name.

The name of the user folder is used for many applications and can create problems if changed later.  I can start over with Dell migrate but I need to know what went wrong so it doesn't repeat.  

1- Why was the email address used instead of the user name?  This has never happened before.

2- To start over with Dell Migrate do I just delete the files, or create a new account, or what?