There can be a lot of reasons for such a problem. For example, your device is weak and it does not have enough resources to run the game. Therefore, the first step is to check the system requirements of the game and the characteristics of your phone.
Also, many errors occur after the update. In this case, I recommend reinstalling the game or checking the update in the app store, as it is possible that the developers knew about this problem and released a patch correcting the errors.

Poor Internet connection or no connection at all. Make sure that your Internet is working properly and restart the router.
