I can see that I’m getting the preferred_username claim back when I request user info, but I don’t see where it gets set in the Okta server. Sometimes it’s the same as the email address but sometimes it’s not.
This question was asked and closed without being answered previously so I’m asking again:
How can I change the value of the that claim in an Okta user’s profile?
preferred_username comes from the Username set in the Application User Profile, so its value depends on whether or not this attribute is being overridden in Profile Mappings (from Okta to App)