Is there a way to synchronize the widget clock with the computer clock?

It appears your Mac is configured to use a timezone other than the timezone being used by your Clock widget.

Date & Time on Mac can be configured in numerous ways. To change these settings, open System Settings, click General in the sidebar, then click Date & Time on the right. You can learn about each of these settings from the following support article: Change Date & Time settings on Mac - Apple Support

jeffg59 wrote:

Once again my clock in the upper right hand corner is 3 hrs behind but the widget is correct!

verify your software is up to date…

The current stable release of Sonoma including bug fixes, security updates is macOS 14.5

Keep your Mac up to date - Apple Support

You can Set it manually, no harm there—the option is toggle OFF "Automatically." I would do what works.

for a corrupt plist, from the Terminal.app copy & paste:

sudo rm /var/db/timed/com.apple.timed.plist

this will remove the corrupt plist. reboot and compare your results

(note—your psswd will not echo on screen, type it in anyway use the enter\return key to proceed. Then quit Terminal.app) Reboot if necessary.