So I have my background set to change to another picture in a slideshow once a day, but I often use the laptop unplugged, and the slideshow doesn't change.

The first few days I was confused, but then I realized that the option "Allow slideshow when on battery power" was turned off, so i turned it on, but the background still wouldn't change the next day. I've now realized that every time I close Settings, the option defaults to "off".

How can I fix this?