For the past several weeks, I’ve been getting no audio from my Tablo Quad on our primary TV (where I traditionally use the Xbox One Tablo app).
I’ve double checked that surround sound is off, but no dice. The tablo has been restarted more than once in the interim. It works just fine on other TVs on the Roku app, and also works fine on the Tablo app for Windows 10 (where I grabbed the screen shots from).
Tablo Device: 2.2.28
HTML Application: 1.7.3 build 204 
Host Application: 1.703.204