In my test I did not put the username as the email, it only gave me the option when registering to put the email and password, as a consequence, it created a username with the email. But now that I try again, maybe it was not your plugin, because yours did ask me about everything, how bad it was that it gave an error in captcha because it was not seen (I have ultimatemember and I have not followed the steps you indicate to put captcha, yet ).
anyway, for example my usual admin user, if you have your user https://prnt.sc/vwdjvs set correctly, and the plugin puts my email address https://prnt.sc/vwdjbl. The generic student now if it works out … https://www.arde.cc/profile/AlumnoGenerico/
note: the url of the web does not work, it does not redirect to the web put in the profile.
thanks.