Login Picture for Settings not saving or "sticking"
I was having a problem getting the icon of my choice to save, but I have figured this out and want to share the solution.
To change your icon in System Settings.
1) Apple icon > System Settings
2) Scroll down the left column to "Users & Groups"
3) Click the Information, circled "I"
4) Click the small, current icon on the left of your name
5) This will open where to select or create your emoji, memoji, or photo
6) Select your choice and click "Save" and then "Done" when it goes back to the "Users & Groups" tab
Previously, I had been trying to change this icon from the very top of the System Settings page and it just doesn't work from that starting point for whatever reason. Try the method outlined here, and I hope this helps.
MacBook Pro 16″