Does the issue only occur on a specific channel or all channels on your Roku device?
We recommend starting here to troubleshoot channel issues: Follow these steps in order:
1.Navigate to the channel tile on the Roku home screen, press the * key on your remote, and choose 'Remove channel'.
2.Next, restart your device from Settings>System>System restart. (For Roku TV Settings>System>Power>System restart)
3.Once your player/TV starts up again, go to 'Streaming Channels' on the Home screen, and add the channel back once more.
You may also refer to this link: How do I resolve channel playback issues? | Official Roku ...
Please try doing this and see if it helps with what you're experiencing.