I have been using this chromebox connected to a TV for 1 1/2 years and it works fine.
Few weeks ago after an OS update the chromebox started to have audio problem:
Quite suddenly voice messages won't play and videos (from chrome browser) won't play unless you mute the audio. You have to reboot to fix the problem and soon the same thing happens again.
It has been going on for a few weeks now and surprisingly the most recent os update does not fix the problem.