Thanks for the post.
Did you restart your Roku device before re-installing the channel? That step is crucial when performing the troubleshooting. If you haven't tried the suggested order, we would recommend giving it a shot once again.
Moreover, if the issue persists on one channel, videos from other channels play fine, there's likely an issue within that specific channel that needs to be addressed with an update from the channel developer. Channels on Roku are maintained by the channel developer themselves. We would recommend reaching out to ITV Hub Support to report the issue and get help.
We appreciate your understanding.
All the best,
Roku Forum Moderator