Could you tell us more about the issue you're experiencing? Are you getting an error message?
Moreover, for more information about that channel's features and functionality, you'll want to contact the channel's customer support team to inquire further. Many channels on Roku are developed and maintained by the channel provider themselves.
Does the issue only occur on a specific channel or across other channels installed on your Roku device?
If you haven't tried yet, you can remove the affected channel then re-install it. To ensure the process is successful, make sure to restart your device before adding the channel back in. We would recommend doing this from the Settings menu by navigating to Settings > System > System restart > Restart.
If the issue remains unresolved, I'd recommend reaching out to the channel provider directly to report the issue and request additional support. Many channels on the Roku platform are developed and maintained by the channel provider directly, and they'll be able to best assist. If other channels are working correctly, and you only experience this issue on that channel (app), that is likely an indication that the issue lies within that particular channel. In these cases, the channel provider will need to investigate the issue in order to help resolve it.
We recommend trying 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.
If that still doesn't clear up the issue you're experiencing, we recommend contacting the channel provider directly to follow up for more help. They’ll be able to best assist with any issues that are occurring within their channel.