Before I saw your reply I started again from scratch and still got nothing. But then I added in the “-admin” you suggested and that worked.
Why did adding that he was an admin make a difference?
There are two Paul Hill accounts, an admin and a regular user(check the Active Directory Users and Computers OU).
From the screenshots, it seems the value was entered in the admin account, and in PowerShell was displayed the regular account.
Since this is a not default value (serverAcademyID) it was not displayed when using * or when using the -Properties serverAcademyID, not even if empty for paul.hill account.
Check the following answer from TechNet forums: