My xfinity app is not working.
Do any other application or channels work? If they do, it could be just the app. I recommend you remove it and reinstall. That may fix the glitch
Here's the link to remove:
https://support.roku.com/en-ca/article/232010488
And to install:
https://support.roku.com/en-ca/article/208756388
I hope this helps!