My hardware setup:

Mezzmo Pro Server 6.0.6.0 running on Windows 10 PC
Mezzmo Client running on Sony Bravia TV KD-55X75CH attached to home LAN
Optical digital audio output connected to Sony Receiver/amp STR-K750P

If I take a USB flash drive, with a movie on it, and plug it into the USB port on the TV, I can use the default "Media Player" app on the Sony Bravia to play the movie and will get 5.1 audio on my receiver/amp.
If I take the same setup and use the local Mezzmo media server to play the file, I only get PCM48 stereo.
If I use the Mezzmo server running on my PC, I still only get PCM48 stereo.

Is there a setting in Mezzmo I am missing?

Thanks,