I'm getting caller unknown as well:
If i'm receiving call - everything works fine.
If i'm calling - after the call caller becomes: unknown.
Did you try clearing the Google Dialer's data?
Sent from my GT-I9505G using XDA Free mobile app
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer? | Terms of Service