Hey, John!
I'm not a tech, but this is a pretty straightforward fix.
The printer can ONLY see a 2.4 Ghz network, so you must ensure your router is also broadcasting on that frequency. You'll find instructions on the Xfinity site HERE.
If you have a computer, try the wizard on this site: https://canon.us/setupTS9521C
Following those steps, you should be good to go, but if you find you still need help, please let us know!
