On my LG TV I can not hear the sound of some video MP4 (for example, some captured from YouTube).
After several tests I noticed that the audio works only if the videos are not great:

I tried to cut a piece of a video MP4 and save the selection without re-encode neither audio nor video
and the TV has no problems!!!

If I increase the length of the cut piece to include almost all the video then the problem of unsupported audio returns

Is there anyone who has had similar problems?

THANX!