I have the same issue with my two Samsungs. I talked to Xfinity last night and was told that they are aware of it. Looks like this happened to LG's also . If you click on one of the suggested shows floating above the Xfinity stream beta app, you might be able to sneak your way into the app.
There was a recent connectivity issue to some of the services required for the app launch and sign in process on our Smart TV platforms. A fix was deployed this morning which should have cleared it up. Can you please try again, and send me a direct message if you are still encountering issues? Sorry for the inconvenience, and happy streaming!
I’m at the same position on my screen. Has anyone been able to figure out what’s going on?
uninstall the app. unplug the TV for 3+ minutes. plug back in and reinstall app. sign in and carefully accept the terms and conditions of using the app as you sign in. working?