I am using an old iPad -- it's an iPad 2 model MC990LL/A -- running iOS 9.3.5 I noticed when I go to settings --> iCloud and tap the top part where my name and ID is, I get this:
Account Details Unavailable
If you are signing in to iCloud on another device or at iCloud.com, you can get a verification code while offline.
I tap "Get verification code" and it sends one -- but where do I put it in? I saw the answers that said to tack it onto the end of your password but there's no password prompt!
I wanted to add my iPad to my list of trusted devices (my phone and computer are there) but there does not seem to be a way to do it.
Any help appreciated.
ETA: The help offere by bmike was great; as it happened turning it off and on again a couple of times did the trick after I reset the settings. (Not a full restore). But dang, the back compatibility is starting to go...