Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
That reply from Paramount was completely unacceptable. Even though it is clearly a CBS Interactive issue, and not Roku, we've had to leave the platform entirely and go to Fire Stick (where it appears to work) as it's that big an issue in this house. But MANY thanks to everyone here for the suggestions.
Select to "Watch credits" and then mash the heck out of the replay button (button with the circular rewind icon on it). I press the button about 6-10 times very quickly and the video goes back to the beginning.