Is the TCL TV a Roku TV? Whether it is or not, you need to use the TV's remote to return to the TV's Home Screen, or menu, or whatever to get off of the Roku's input. If it's a Roku TV, press Home on the TV's remote.
You may want to turn off "1-touch play" on your Ultra. Using the Roku's remote, press Home a couple of times to get to the Home Screen and then using the menu on the left side of the screen navigate to Settings->System->Control other devices and uncheck "1-touch play". That option tells your TV to switch to the Ultra's input when you press a button on your Roku remote. You may or may not find that feature desirable.
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