For Windows 11/10 Home users, you can add Local Group Policy Editor and then carry out the instructions as provided above. Your lock screen wallpaper keeps changing because the Background setting ...

The new Bing Wallpaper ... of Windows Spotlight that offered users a pleasing visual experience each time they chose to run their computer. It also let users vote those images for the lock screen ...

It even has wallpapers if you want them. It does take some time to start; there’s usually a two to five-second delay every time you open your lock screen ... mint, dark background, and beige.