What's the model number of your Roku device displayed under Settings->System->About. Note that Roku devices only support channels 1-11 on 2.4GHz and not all devices support 5GHz and those that do don't support all channels.
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.
I am not a Roku employee.