I have just received the device and it is connected to TV using HDMI cable.
It is using VIM2_Nougat_V170831 firmware, that came out of the box.
The HDMI Resolution used is : 1080p-24hz (format is YCbCr444 8bit)
The audio settings are : Surround Sound (Never), Dolby sounds (OFF) , Digital Sounds (HDMI) , Dts Sounds (0)
When i open You Tube Application the sound initially works, after stopping or changing the video. The audio is no longer available (no sound is output from the TV). The same is valid for other apps.
It might randomly start working after closing / re-opening apps but in general most often it does not work.
Unfortunately what i observe is the audio occasionally working/non working. For example it has started working during youtube playback, and then stopped again after i paused and re-started the clip.
I have no explanation for the inconsistent behavior - could it be a cable issue i do not know, since the video works fine.