Hi @Adrian6,
Warm greetings from the Roku Community!
After attempting the troubleshooting steps and videos from other channels play fine, contact the channel provider's customer support team to report the issue and get help. Channels on Roku are maintained by the channel developers themselves. In this case, there's likely an issue within that specific channel that needs to be addressed with an update from them.
If you need anything else, please let us know.
Sincere regards,
John
John
Roku Community Moderator