Good Day Everyone. I'm submitting this question in August, 2020.
Comcast Xfinity's website provides a list of specific model numbers of Roku devices that are compatible with its "beta" streaming app. However, I'm wondering if that list is current, and also wondering if the app has moved beyond a "beta" version. I'm wondering if newer Roku versions (other than those which Xfinity shows at the moment) are also compatible. Perhaps their listing needs to be updated? Don't know...and it appears difficult to find out directly from Comcast.
I bought the Roku Ultra 4800R and can confirm that it does not work on it. it gets through the whole setup and logging in but it is frozen at a show that it says I bought and it is the only thing I can click on. I tried to re-add Xfinity and log back in and still the same. I called Xfinity and they have no clue or information on when it will work with that model, they told me it is not supported for the 4800R.