Thanks for the post.
We would always recommend powering the Roku device to a wall outlet and not through the TV USB port as at times the device may not be able to provide adequate power to the device.
If you are still experiencing an issue, we would recommend removing the channel(s), restarting the Roku device, and then adding the channel back again, specifically in that order.
Please keep us posted what you find out and we will be able to assist you further.
Roku Community Moderator