Apple ID Verification Failed: Unknown Error Occurred.
Both my phone and apple TV keep asking me to re-sign in with my Apple ID, then say unknown error occurred after I enter my password. I've restarted both numerous times, and the password works when I sign in online and on my mac. I recently had a phone stolen (and deactivated it by reporting it as lost through my apple ID), so this phone is new after that.
iPhone X, iOS 11.3, Also Apple TV 2