Have you tried ALL of the codes listed here: https://customer.xfinity.com/remotes/
I used to have an older Denon and there was a code that worked for the XR11 remote.
FYI there is also a manual code search process...
Eggman1 wrote:New voice remote is paired to TV and controls fine. Trying to pair to receiver and have tried all codes that are offered at setup for Comcast. Any ideas?