Changing the attributes for userFullnameAttribute in the Portal for ArcGIS Update Identity Store page does not update the user's account automatically.

Workaround

1. In the Portal administrator account, navigate to the user's profile, select edit, and select save.
   1. This changes the user's stored full name from LastName, FirstName to FirstName LastName.
2. Affected users can login to Portal for ArcGIS, which makes the changes to the way the name is stored.

Steps to Reproduce