When a preparer logs in and changes the display in the Personal Client Manager, the changes are not there when the preparer logs in later.
The preparer is probably using the X button to close Drake, which does not save the changes. The preparer should exit the software by logging out, pressing Esc, or by using File > Exit. Those methods of closing the software will save changes to the PCM.
The PCM is enabled at Setup > Options, on the Administrative Options tab.