I was charged my monthly fee for the Topic service on July 5th. But now, just after midnight Central time on July 7th, I get a message that I am not subscribed to Topic when attempting to launch an episode. Not cool.
Did you subscribe to the channel through Roku Pay or did you subscribe through the channel provider directly?
Try removing the channel from the Roku home screen by navigating to the channel tile, pressing the * key on your remote and choosing 'Remove channel'. Then restart your device from Settings>System>System restart. Once your player starts up again, add the channel back once more.
Does this clear up the issue you are seeing? Please keep us posted what you find out.