Helix TV Terminal losing HDMI audio signal

Since the installation a few days ago, it's been working fine.

This morning I turn the TV on, there is picture, no sound.

I checked if the sound bar is on, it was.

I then checked the TV speakers, they were working.

I tried resetting the box, the TV, and checked all the wires.

Everything was ok.

I tried the TV's Smart apps to see if they had sound. 

I selected YouTube, clicked a video, and audio was now working thru the sound bar.

When I changed to the Helix TV terminal, it too was now sending audio thru the sound bar.

Sound bar uses HDMI ARC cable.  Does the Helix terminal also require an ARC port?