You need to set it back to Picture or Slideshow according to your ... Click on Change advanced power settings. It will open a Power Options popup window. Scroll down to Desktop background settings ...

Next, select and click on a theme you want to apply ... and click on Set as desktop background. To let Windows 10 change your wallpaper automatically, select Slideshow from the drop-down menu ...

As first spotted by @PhantomOfEarth, one of the options available in the Copilot for Photos app is the ability to set your favorite photo as desktop wallpaper. So, instead of following the ...