I want to change what can and can't use cellular data on my phone but the area with the toggle buttons is frozen and won't let me change any of them. How do I fix that?

I am trying to enable cellular data usage for my contacts and mail, but the rifle switches under the cellular data heading are frozen for everything. I was having the same problem with Safari but fixed that by resetting network settings, an I am still having it with a few other apps also. How can I unfreeze the toggles? I've tried everything I can think of, and my software is up to date. Help???