Hi Robin, glad to help, I have only had mine a few weeks and it takes a bit of getting used to. I have had some great help on this forum.
doesn't switch to the correct input channel, or he shuts down
the TV when its is not supposed to do that...
It is worth spending a bit of time on Power settings and Input settings. A lot of trouble seems to be caused by buttons that toggle. It may be that your TV POWER is the same button for ON & OFF. If you check in the additional buttons for your device you may see that it shows discrete commands for ON & OFF, in which case go through to Device>Power settings>want to turn off when not in use>button for ON and button for OFF> don't have Remote but know commands and change to the discrete ones you found.
Hope that helps
Alan