Please follow the below steps:
1. View other apps or webpages to confirm if the network is working normally. Confirm whether mobile data is turned on. Check whether your mobile phone data package has exceeded its limitation. Or try using WiFi.
2. Exit the game, remove the background cache and then re-enter the game. Find the game app in Settings>Apps>See All Apps. Go to Storage & Cache in the game settings to clear the cache.
4. If the above methods don't work, uninstall the game and download it again.
If the issue persists, contact the Nothing Support Team for further assistance.