I am having this exact same problem. Unauthorized devices streaming on my Xfinity Stream account.
No other "users" listed on my Xfinity Account. No users on my Xfinity Xfi account accessing my Router. The ONLY thing they are accessing is Xfinity Stream and they are purchasing hundreds of dollars of content.
I was on hold with Xfinity on the support phone number last night for over two hours and the representative wasn't able to answer the issue. I entered online chat and waited as 370th customer in the queue and was told to change my password, which I've done.
This morning the unauthorized user is on the account again. I've asked SPECIFICALLY to "deprovision all devices from the Xfinity Stream app" and have not found a rep who can do that.
Apologies for the issue and the experience that you described above. We have a specialized team that can help with this. Some options to reach that team are listed below:
Comcast Security Assurance Toll-Free Number for General Requests: 1-888-565-4329
Good overview website https://internetsecurity.xfinity.com/help/report-abuse/
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