Unable to change the time zone in Windows 10

I'm running Windows 10 Pro. My time zone is Jerusalem, but I need to change it to Eastern to test a program I'm working on.

The time zone won't change. I have tried:

• From the clock/calendar, when I change it - it changes back.
• From Control Panel - Date and Time, "Change time zone..." - when I click save I get the message "Error occurred - your changes could not be saved."
• As the Built-in Administrator from the command line using tzutil - I get the message "Insufficient privileges to set the current time zone."

The registry key TimeZoneInformation has Full Control for Administrators

Administrators are listed in the Local Security Setting "Change the Time Zone"

Any suggestions?