Background App Refresh

If you are unable to change the settings:

Settings -> General -> Restrictions - enter your pin code.  Scroll to the bottom, Background App Refresh is under the "Allow Changes” section. Can you check that "Allow Changes" is on.

I think he meant settings > screen time > content and privacy restrictions

you can refer to a similar issue, https://discussions.apple.com/thread/8573987

Ok go to settings >> screen time >> scroll down to "content and privacy restriction" >> background app activities >> allow it.

then you can go back to settings >> background app refresh and turn it off

With pleasure 😊