However, this feature may not work on your box.
Then, you want to know what to do if Windows 10 slideshow background not working.
This post shows you some effective solutions.

Windows 10 slideshow wallpaper is a welcomed feature.
Ifyou have enabled it, the system will shuffle the background pictures as per your configs.
However, Windows 10 slideshow background may stop working due to some reason.

That is, your Windows 10 background slideshow not changing as you expect.
it’s possible for you to try these methods to help you out.
How to Fix Windows 10 Background Slideshow Not Working?

it’s possible for you to go toStart > configs > Personalisation > Backgroundto check ifSlideshowis selected underBackground.
If not, just do it.
But you could manually allow slideshow when on battery power.
If not, turn it on.
This is not what you want.
The pictures in a sub-folder will not be looped as your Windows 10 background slideshow.
However, you better confirm that there is an availableWindows restore point.
If not, this method is unavailable.
You may need to reinstall your Windows OS to have a try.
Bottom Line
We hope the methods mentioned in this post are useful to you.
If you have other useful approaches, you could let us know in the comment.