Configure Proguard-rules with Firebase

I've this project and i use Firebase Realtime Database.

It's correct write this proguard rules?

-keepattributes Signature

-keepclassmembers class activity.** {
  *;
}
-keepclassmembers class adapter.** {
   *;
}
-keepclassmembers class fragment.** {
  *;
}
-keepclassmembers class persistence.** {
  *;
}
-keepclassmembers class services.** {
   *;
}

The app work perfectly but when i release on PlayStore it seem that the query doesn't work. In my gradle i added

release {
        minifyEnabled true
        proguardFiles getDefaultProguardFile('proguard-android.txt'),
                'proguard-rules.pro'
    }

what did I do wrong?

You should -keep for classes that will be serialized/deserialized by firebase, otherwise it won't be able to use reflection on those classes. -keepclassmembers will only keep the members and obfuscate the name of the class, which is something you definitely don't want to do if your libs use reflection. Try replacing -keepclassmembers with -keep for those classes.

-keep class persistence.** {
  *;
}