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.
I just checked the Channel Store, and there is a Game Show Network channel. However, it has the following caveat: CABLE OR SATELLITE SUBSCRIPTION REQUIRED.
Now, you have Mediacom, so that might qualify. I'm leery, since that particular channel isn't in their lineup. Only GSN can can answer for sure if your provider meets the subscription requirement.
Dan Roku Stick (3600), Ultra (4640), Ultra (4670), Ultra (4800), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.