Updating Account User Picture

I have an older Macbook Pro (2011) running on MacOS Catalina and my account picture will not update. When I try to update it, none of my pictures in Photos show up; they appear as (JPEG, HEIC, etc.) but you can't see the picture. My photo for my all my iCloud accounts and apps appear with the updated picture I currently have but it's only under "Users & Group" where I can't updated the user picture. Also I when I open "System Preferences", my iCloud picture isn't updated either. It's my previous one from few years ago and I haven't ben able to figure out how to update it either.

I appreciate the help!