Apple ID photo reverting back to prior image?

I've seen a lot of questions regarding users who have attempted to change their Apple ID photo, only to have it revert back to the prior image.

If you're experiencing that very frustrating scenario and you have already tried to change it (multiple times?) in Apple ID Settings and/or by logging into iCloud, then try this:

Go to System Preferences > Users & Groups. Unlock your profile (if it is locked) and change your photo there. This would particularly important to do if you are the/an Admin on that device. Re-lock your profile (if applicable) and... voila!

Hope this helps.