Unknown device connected

I have a connected device in the Xfinity app called "Valued Customer" that is showing activity with an IP address that is not in my household.
I purchased a laptop from CDI through Comcast which has a different IP address and the app indicates "not connected", yet it is.
I'm not sure how to correct this, getting through to a real person rep with Xfinity is a challenge. Any idea how I remove the unknown connection? I have tried using "connect" in the app for the new laptop, but it just says device not connected.