Phone calls not stopping MPD songs

I have a Xperia Z1 Android phone with this application (Mupeace) installed from Google Store, so the last build in installed on it.
I run mpd on my raspi 2 B (900 Mhz) and I am not able to pause music while receiving a phone call.
While with my old raspi 1 I was able to pause playing music on phone calls.

Is there a problem with mpd configuration or with Android app?

Regards,
Stefano.