Hey @Blessed29546, I hope you're doing well.
Is this on your lock screen or home screen (or both)? Do you have any wallpaper apps installed? I know some wallpapers apps that I've downloaded from Google Play have an option to cycle between a variety of wallpapers.
If you do have a downloaded wallpaper app installed, please check the settings in the app. If this is happening on the lock screen only, please go to Settings>Wallpaper>Wallpaper services>Select "None". If it is on Dynamic Lock screen, it will change wallpapers every time you get to the lock screen.
Let me know if any of this helps.
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