Streaming is glitchy

I have two cable boxes in the home and use xfinity stream on the other three TV's. All other apps work very well except for Xfinity. The issues are:

• I have to use the back button in order for the Xfinty App to start working on one of the TV's
• When searching for "movies on live tv" through the app only occasionally do the options show up, you have to power down everything and restart to see the movies that are on live tv now
• The mini screen doesn't display show titles, only the networks 
• The favorites button doesn't work, you can only set up favorite channels on line?
• It freezes up often and I have to page out to get it working again

I pay almost $300 for Xfinity a month, I got rid of a few boxes on the advice of a CSR when I asked how to save some money and the streaming just continues to glitch. When I call, I am told to reset my modem, which does nothing.