Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
I suspect a lot of people are waiting to see if you complete that sentence.
Otherwise, more info would be helpful. Like What channel/app. Or is it one channel or all channels. I ASSUME we're talking about streaming channels but since there are Roku TVs, that could be a wrong assumption. Have you gone into settings and checked your connection? Wi-Fi connections especially can be pretty variable in some environments. (Here again, I am only assuming that you are using Wi-Fi.)