Scenario:
The User Detail report is configured to display User name and Start Date fields only. The only filter enabled is Users. However, when the report is run, it displays the user names multiple times, corresponding to each department the user belongs to. This happens even if the Department field is not enabled.

 

Cause:
This usually happens when Hierarchy Filtering is enabled.
With Hierarchy Filtering enabled visibility to data for a specific user comes from the department to which they are assigned to. Hence all the data (related to a User) would have a reference to the Department by default.
 

 

 

Resolution:
Run the User Details report with the Hierarchy Filtering turned off under System Preferences.
(Enable Hierarchy Filtering after report has been run)