Server problem
Your game is experiencing this problem because your game is not
connected to the server. There can be various problems. Therefore,
check that your game is connected to the server before starting the
game.
At the moment I ask you to check the following steps.
Check app update> Sign out game> Restart device> Open game and
sign in.
If your game app is damaged, you won't be able to sign in or sign out
of the game. Let me know if you see the image below when you sign in or
sign out.