I think I have found the source of the issue. It seems to be a bug in Android version.
Samsung SGS5 Android 5.0 - can not set the expo
Samsung SGS7 Android 5.1.1 - can not set the expo
Nexus Asus 7“ Android 6.0.1 - can not set the expo
iPhone 5S – works
I will try to test iPhone 6 and 6S, but I am sure, that the issue is related to Android.