Pluto TV weirdness

[UKBB]

We have a Samsung MU630D TV and I was getting annoyed by the OTA antenna dropping data and causing pixelation. A coworker said that Pluto TV includes local stations so I switched over to the Roku box and installed the Pluto channel. When you pick a channel you like you hit the * button on the remote to make it full screen. But when I hit the back button to go back to the channel guide it doesn't work. For whatever reason though if I hit the back button on the TV remote it does take it back to the Pluto TV Guide. Really bizarre. I never did find the game on their listing but I didn't activate Pluto TV either so maybe I need to do that to get my locals.