Can't log into Microsoft Sudoku for last 2 days - it won't login to XBox

I just installed the latest update, and it won't load. What is happening is that it's failing to login to xbox.com from the xbox apps. I can login to xbox.com in edge AND chrome, but I start Microsoft Sudoku and it tells me it's sorry but it can't log me
in right now, try logging in to xbox.com and restarting the app.

Obviously they have problems, but support from Microsoft seems to be at their traditional level: useless.

Yes, the last 2 days, Sudoku won't open or closes unexpectedly. What's up?

I have the exact same problem. Have uninstalled and reinstalled. Can click on the green xbox button in the upper right corner of Sudoku, and sign into xbox just fine, but Sudoku can't sign in. Have even exited Sudoku, and punched the "Play Sudoku" button
within xbox, which starts Sudoku, but Sudoku still can't connect. All of my other games work fine.

I have seen a message from time to time within Sudoku over the last 2 days which seems to say that this is a new version and you don't have to sign into xbox to play, but then I lose all my history of what has happened in the last 4 years. The message disappears
before I can study it. Is this a new version? Or maybe I am misinterpreting the message.

Having same problem. Will log into all other games but not Sudoku. I have been trying for 2 days now.

Can't log in it won't recognize my login.