Xfinity App blocks unlocked samsung galaxy S25

The Xfinity app used to work on my old Samsung Galaxy S8, until suddenly it stopped. Now I have a brand new unlocked Samsung Galaxy S25+ with a Consumer Cellular sim card. The phone's software is up to date. I was looking forward to using Xfinity app to manage my Comcast router again. I downloaded and installed the app, verified my phone's location and connection settings were available to the app, checked my Xfinity account has two factor authentication enabled. And I struggled for an hour trying to authenticate from the app. The Xfinity AI chat pops up instructions for resetting my account password, which I tried - that does not work either.

This is totally unacceptable, Xfinity! What do you think happens when power goes out, Xfinity cable internet goes out, and there's no wifi to connect to? Your customers use their cell phones and data to access utilities and service providers. Fix the app, and and provide app-specific support and instructions on your internet site.