That hasn't been my experience, in lots of years of having to call them and make them fix dumb things. Once you get past the "no, I am quite sure there is no wi

That hasn't been my experience, in lots of years of having to call them and make them fix dumb things. Once you get past the "no, I am quite sure there is no wifi interference on this cat5e cable" bit of the Generic Support Script, they do seem to be capable of understanding where the problem could plausibly be. (Ability to do anything about it varies.) They even helpfully provide a compatibility list: https://www.xfinity.com/support/devices/#unauth https://www.xfinity.com/support/devices/#unauth