So here's my audio setup.

I have a GTX970 which is connected via HDMI 2.0 to my Vizio M70-C3 tv. My Vizio 5.1 Soundbar is connected via the included HDMI cable from the soundbar to the ARC hdmi port on the TV.

What is happening is that I'll go away from my PC for 5-10 minutes to 8hrs and when I come back and try to play a movie or watch any video online (youtube) there is no sound. But when I restart the "Windows Audio" service, sound comes back on.

I tried setting the TV's CEC function to ARC only but I still encounter the same issue. I also changed the power settings on my PC so that the screen and PC don't shut down, but when I turn off the TV, which also turns off the soundbar (which I do when leaving for work) the problem arises and I lose sound again.

I ran the Windows Audio Troubleshooter and selected the Realtek sound option but it told me that no devices are connected.

Any ideas at all on how to fix this?