Thanks for reaching out here in the Community!
We would recommend starting with the troubleshooting steps in this Support article: How to resolve issues with your Roku® simple remote or Roku voice remote.
If the issue persists after attempting the suggestion above, contact the TV manufacturer directly to report the issue and get help. Remotes for Roku TVs are manufactured directly by the TV manufacturer.
For a list of Roku TV manufacturers contact information, visit our Community post here: Contacting Support for Your Roku TV
All the best,