I tried to get an answer to similar questions through chat.....this is was the brain trust at Xfinity came back with as a resolution:
Just to set the right expectation, We have to do some troubleshooting to fix On demand issue which may require powercycle or reset to the box. After that Box will sync with the server to reload all the On demand contents on the box. Whenever we do powercycle or reset of the box and it takes around 60 minutes to reload content, Meanwhile TV shows will work fine.
This company is oblivious.