Win10Pro lock screen before user login, can I change it?

Hello, I run Win10P 21H2 19044.1706. Some months back I started to see the same image from the Windows Spotlight delivery system for weeks. I changed my user lock screen but that does not change that image shown before user login.
I hate it and this started after I clicked on the lock screen to say I did not like it. Then I turned off Spotlight and set my picture to the lock screen. Now it's in my face every boot.
Does anyone know where that image is hiding?

Thanks for the replies. I used gped and set "Do not display the lock screen" to enabled. That stopped the image from appearing on a lock screen but moved it to the login screen and overrode my setting for a background image. Then I set it back to not configured and tried "Prevent changing lock screen and logon image". That stopped that wayward image from appearing after a boot. No if I lock the screen I see the image I selected. But things are still screwy. I cannot enable the Windows Spotlight. It just switches back to Picture. Things are livable but there are some disfunctional things in this system.

Hi Compumind, I have agree gpedit is just a pretty editor for the registry and can be trouble. I went into the link and found that Edge is not listed in my background apps. I found other posts about that problem. One in the microsoft community says microsoft left it out in this version of windows. But I did go into Edge to be sure it was set to run in the background and then did the rest of the steps and Spotlight is now running. I think that was important as the behavior of the lockscreen and startup screen were strange. I noticed that prior to the Re-register Windows Spotlight the startup screen default was getting set to my accent color. I did not expect that. Thanks for the bat file.
I believe that having a corrupted Spotlight was causing very strange things to happen with my lockscreens and backgrounds.
Really big THANKS