User does not want any amount to show under Extra Services in Projects > Performance screen.
The Extra Services on the Margins widget of the Projects > Performance screen shows the data from the Extra time entries on that project. Check CORE Help Center for details. If you think there should be no Extra time entries on the project, you can Batch Update the Extra flag to False for all such entries, provided they are not linked to invoices. Check CORE Help Center for details on that.