Hi @cottrillhouse, Please take a look at our Parental controls article https://www.xfinity.com/support/articles/set-up-parental-controls-with-comcast-networking, it is the overview for Parental Controls.
I've taken a close look at all blocking options via xFi and can't find a way to block specific websites (e.g. youtube.com) under Parental Controls. Is this not a feature yet?
I've also tried to do this via my Xfinity router configuration per other threads (Parental Controls -> Managed Sites) without success. Here is my router detail in case there is a known version that doesn't work. Suggestions?