Are both devices compatible?
I run Empires on two apple devices. Once I update on one device, I have to update the other device.
I make sure to update my iPod ( iOS 9 ? ) first because eventually Empires will not run on it. Then I will have to decide between replacing it with a newer device or just playing Empires on a single device.
I do not know how the Android partial roll out works, but you may have to download an APK to get the latest version on both devices especially if they are linked to different Google Play accounts.