Hi @Fraidykatt,
Welcome to the Roku Community!
Thanks for reaching out here about this. If I understand it correctly, this is an OTA channel you're accessing right on your Roku TV?
Your Roku soundbar doesn't have the ability like this (How to set up the Antenna TV input on your Roku TV). You can only access local channels within The Roku Channel which are limited stations. This is likely the reason why you're not able to get the rest of the channels you're trying to access.
Or let us know more about this so that we can further assist you.
Thanks,
Rey
ERey.
Roku Community Moderator