Renamed account not updating active directory
The minimum naming information for a user account requires that you configure Full Name, Logon name, and Pre-2k Logon name (as per the Active Directory Users and Computers (ADUC) user creation wizard), which the final resulting attributes can be seen in Figure 1. Minimum Name related attributes for a newly created user account.
If you want to change the name that is showing up in the ADUC view, you can modify the attributes manually. ADUC does not display the user account displayname attribute.
The solution: The answer is that you didn't do anything wrong.
After completing those steps, the user should receive an welcome email for the Groups they've been added to. Deleting the user from the site collection and adding them worked for me.
For some reason trying to update via Power Shell kept throwing an invalid user identity error or Access Denied, depending on which site collection the user was in.
However the incorrect old display name is not updated in Share Point People Picker and still shows the old name.
The "User's Security Identifier" (SID) of the user did not change.
Everything synced up pretty well, but the problem was that the E-mail field in AD UPN didn’t match the 365 username.
The account worked, but had mismatches with the send from field and signing into Outlook.
Instead, you will be looking for the cn and name, which is updated with the actions from above. Imagine you only need to update the displayed name for a single user account.
The behavior appears to be that the account name is not changed.
I had a users initials as their First and Last name, and they asked me to put their full name in. I know sometimes these changes are not done right away, but its been a few hours. There are actually 6 fields that control user's name and username, and the only way in GUI to ensure you change them all is to do what Patrick and Vick Vega suggests.