Synchronization can only be performed between the same platform. For synchronization use the same account on both devices.
For iOS devices
Please make sure you are connected to your iCloud account on this device ('Settings> 'Game Center).
Start the game and wait until its previous status is restored.
However, keep in mind that progress can be restored only if you previously played by connecting to the same account.
For Android devices
You can restore your progress by re-entering your Google Play account in the settings menu of your devices. You will need to wait until the previous status of the game is restored. This can take up to 10 minutes.
Please make sure that you are connected to the same account in the Google Play Games application.