In the menu it's displaying as surround and doesn't change. It's the output that is changing. The surround sound has a LCD screen that indicates the sound type coming out and after a while of PCM 2.0 it will switch back to DD 5.1 but nothing in the PVR changes. I am looking into if it's the sound quality the networks are broadcasting or if it's a technical issue. It's happened on Stingray also which should always be 4K, PCM 2.0. Let me know if you think of anything!