Hi master_lorn,
So support at Xfinity is a bit slowish at the moment. I submitted all the info they requested and waiting for further analysis from their end. In the meantime, they suggested that you install the xFI app yourself which will allow you to maintain an internal whitelist of allowed applications and domains so our software won’t get blocked and you can still enjoy protection while running it. This would also allow you to see a detailed report on why the app/domain was blocked initially, and you can use this report to submit it to their customer support, so they can also investigate your case directly.
I hope this helps, will keep you posted as the case evolves.