When I use the Roku remote to adjust the volume the TV shuts off or Roku shuts off and the screen sits black. It will eventually come back to the main screen but nothing happens when trying to turn the remote or channel on.
Brand and model of tv and of course the roku? I would repair the remote to the roku, then program the tv again, but skip the first code that mutes the music, click no and try a different code later on in the process. See if you have better outcome.
We are trying to get the remote to use a different code then the one that turns off the tv, so just pairing it to the roku again wasn't all I asked you to do, you were to program it for tv, and skip the first positive result and try a subsequent code.
settings> remote & devices> remote in use> program tv> now follow the prompts but skip the first one that mutes the music and try one further on.