If you noticed that the game can't be opened only when you are connected to your Wi-Fi, the source of the issue may be on your internet provider's side or in your device settings. However, you can always follow these useful recommendations to overcome the problem:
 
1) Restart your device.
2) Reboot the router.
3) Switch on the airplane mode on your device and in a few minutes switch it off.
4) Delete your Wi-Fi network from your device networks list, and add it again.
 
If these steps don't help, please contact the support team of your local internet provider. If the internet provider states that the problem is not on its side, please contact our technical support team.