Sorry for the slow reply, Jayvan. It's taken us a while to look into this.
The issue of the game not saving happens if you are playing the game on a secondary profile on an Android device with Android 4.1+ installed. We are currently looking into this issue but do not have an ETA for an update that addresses it. As a workaround, we suggest that you install and play this game on the primary or master user profile for the device. Please let us know if this does not resolve the issue. Thank you for your patience!