Samsung tv/SONY avr. The Roku Ultra remote will turn the tv on and control volume. However, doesn't turn the tv off. So I programmed one of the numbered buttons on the Roku remote to "tv off". So now, I press #2 to turn the tv off.
I had had the same issue with my Panasonic plasma. I finally thought to unpair/remove (via settings in roku) my existing broken roku remote and pair my new roku remote and it finally recognized the Panasonic TV. Interesting thing was that my old roku remote continued to work as well.
Finally got my Roku working with Panny 65st50 & Vizio Soundbar! Setup remote to "Vizio" when selecting tv brand. The 2nd or 3rd code turned the sound off, so remote volume controlled the SB. I used theroku voice/mic to say "turn off TV" and it went off. Now the mic button turned it back on. Weird, but usable.