Thanks for reaching out here in the Community!
Have you tried removing the channel then adding it back in? If not, we would recommend giving it a shot. Make sure to restart your Roku device before re-installing Paramount Plus to ensure the process is successful.
You can follow the step-by-step troubleshooting in this Support article: How do I resolve channel playback issues?
Let us know how it goes.
All the best,
Roku Forum Moderator