I've never heard of that happening, but it must be something CEC related. In either your TV settings or the Roku settings, disable CEC. On the Roku, it's likely under System/Control Other Devices. Depending on the player, it might just say 1-touch play, or actually have a CEC function listed. Just turn it off.
Of course, it could be a defective remote for the TV, and whatever button you are pressing might be sending an input change signal instead of its intended purpose.
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