This is how I have worked around this issue. It is better than replacing the default images with an account picture, as some have done, because it allows each account to have their own unique picture displayed on the login/lock screen. As it should be.
1. Logged in with administrative privileged account.
2. Opened registry editor (RegEdit).
3. Navigated to the user account picture registry key:
4. Right clicked on the users key and selected permissions from the popup menu. ex: S-1-5-21-xxxxxxxxxx-xxxxxxxxxx-xxxxxxxxxx-xxxx]
5. Added "Administrators" group and granted "Full Control".
6. Added new key "Image200", copied value from one of the other keys and changed the value of "Image*.jpg" to "Image200.jpg".
7. Removed "Administrators" group from permissions and verified that keys cannot be created or edited.
Changing the user account picture removes the "Image200" key from the registry.
If someone could figure out how to prevent the "Image200" registry key from being removed, that could turn this workaround into a fix.
In my opinion Microsoft full well knows this issue and created it intentionally to coerce and manipulate people into Windows 10 and 11. This issue had been reported as early as September 2021. It is now January 2023 and such a simple fix still has not been provided.
Reeks of intentional product sabotage for this issue with such a simple solution to go on for so long and never be fixed.