Change channel with my Samsung remote

Trying to change channels with my Samsung remote for Xfinity Stream to get like channel 4 can’t get it to change? 

To change the channel in the Stream app on my Samsung I have to [Return] to the first Stream screen ("Now Playing"), select "Live TV", and scroll-scroll-scroll to the channel I want to watch. "Saved", "Browse", "Search", and "Settings" are also options on that screen.

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