Just got a Roku stick because the remote to our Visio M470SL does not work with the tv. I thought getting this would solve our problem, but the remote won’t pair for volume and the power button now.
You have no remote in the house that actually works the vizio tv? Until you found out for sure the tv is accepting IR commands in the first place you can't assume the roku remote isn't programmed with correct commands.
The remote that came with the tv doesn’t work at all. I tried a universal remote before the roku, which also didn’t work. The roku remote works for controlling the roku, it just won’t pair to the tv to control the on/off button and the volume. We’ve been using the tv’s side buttons.
Three different remotes are proof positive your tv isn't accepting any commands, sorry but your tv is broken.