Thanks for the post.
As others have suggested, we would recommend trying to use another HDMI cable as well as another HDMI input to see if you are still experiencing the same issue. If multiple devices are exhibiting the same issue, then the issue is most likely not the Roku device, but possibly the TV connection or port.
In addition to the above recommended steps, have you tried connecting the device to another TV to see if you are experiencing the same issue?
Please keep us posted what you find out.
Roku Community Moderator