Gamecenter not working - iOS 9.2 - phone 6S

I am having trouble with games on my iphone 6S. The particular game is Galaxy of Heroes, but the issues seems to be that gamecenter gets stuck and doesn't load completely.

I have followed the steps in the following discussion several times - closing all apps and restarting the phone.

Re: Gamecenter isn't working on iOS 9.2

After I have done that, I still have the same problems ...

1) If I open gamecenter using the app icon, I get a blank screen that doesn't go away.

2) if I go to Settings and select GameCenter, the screen hangs and nothing happens.

This has been going on for several days now. Before upgrading to iOS 9.2, the game would hang on the opening screen waiting for gamecenter login, and a phone restart would make the problem go away. After upgrading to iOS 9.2, the app kill and phone restart stopped working.