Hey everyone,
We sincerely apologize for the inconvenience this has caused.
Channels on Roku are developed and maintained by the channel provider themselves. If the suggestion provided by RokuDanny-R above didn't resolve the issue you're experiencing, we would recommend contacting the channel's customer support team to report the issue and get help. There's likely an issue within that specific channel that needs to be addressed with an update from them.
You can reach Hallmark Support here: https://customercare.hmnow.com/hc/en-us/requests/new
All the best,
Kariza