1. You need to have a stable internet connection for the save-system of Shadow Fight 2 to work properly. If the internet connection has been lost then the game progress might be not saved.
2. If you’ve installed the application via App Gallery then you should synchronize your Huawei account with the game. Steps are the same as for Google Play synchronization, but you also need to check the box next to "Obtain your email address" otherwise game progress won't be saved. If you have already synchronized your account, but didn't check the box, then you need to go to App Gallery/Me/Your account/Privacy center/Control account access/SF2 and then press cancel the authorization. Then you should launch the game and perform all the steps, described above.
3. If you did not receive the request for synchronization during the launch of the game then you should complete the tutorial, then go to the Settings (it has an icon of gear in the drop-down menu) and press crossed icon of "Google Play " (Game Center) and synchronize your account. After that, the icon will not be crossed anymore. Now you will be able to save the progress and restore it if you need or transfer it to another device.
4. Remember your UserID (For example, User ID 90013909). You can find it in the Settings.
5. Note that synchronization with Facebook will not allow you to save your progress.