I have found a way to use my Hisense Roku Smart TV remote to operate my Vizio soundbar.
It sounds weird but it is currently working on 2 of my TV's.
1. In TV Settings, Set to HDMI-Arc
2. In the soundbar remote settings, select USB
I don't know why or how it works, because I have nothing plugging into my USB port on my TV. I happened on this fix by accident.