Could Not Sign In: A server problem is blocking Apple ID sign in. Try signing in later." My father's iPhone 7s shows such message:

Could Not Sign In:  A server problem is blocking Apple ID sign in.  Try signing in later."

The passcode screen does not even come up. I have search the Apple Community but there is no answer. Anyone knows how to fix it?
I had the same problem. I found that if I set up the Touch ID and Passcode, it went through. I then could turn off these features after. Hope this helps.