Hello, Kathypollock8. Welcome to the Xfinity Forums.
I would be more than happy to help you troubleshoot this issue.
Can you tell me what kinds of steps you have already taken such as rebooting the device, and checking all cables to ensure they are secure?
You may need to re-pair the remote with your cable box. Press and hold the XFINITY and Info buttons for 5 seconds waiting for the remote light to change from red to green. You should see a message on your TV giving you a code to type in to complete the pairing process. Let me know if this helps you.
Kathypollock8, as I have not heard back from you in some time, I have closed this thread to further comments. I hope you got your remote paired, but if you still need assistance, please feel free to start a new thread.