Nope, sorry, that's not it. I'm not trying to turn off the Roku. But the button does indeed turn it off. No matter how I turn off the tv, whether with the remote or with the button on the tv, the Roku goes off too. (In fact I just noticed that the tv can still be on but the Roku turns itself off.)
But the real problem is that every time I turn off the tv now, whether with the remote or the button on the tv, it takes about 10 minutes to get anything to work again the next time. I turn on the tv, the Roku turns off. Or I press the remote button, the Roku turns off and the tv turns on. Then the sound is now always turned off when the tv comes on. Not mute, the internal speakers are turned off in sound settings on the tv. I need to go into the sound settings every single time and tell the tv to use the tv speakers again, then go out to the tv before the sound will actually come back on, then I can go back to the Roku to get sound on the Roku. It's complete madness.
I just want to TURN OFF tv controls, so the Roku remote has NO EFFECT ON THE TV. How do I do that?