Can't sign into the Xfinity App: "Sorry, That Didn't Go As Planned"

Every time I try to sign into the Xfinity app, the login fails and it displays a screen that says "Sorry, That Didn't Go As Planned".

I've seen posts on this issue in the past, but there was never a good solution. 

Details:

>My login credential are correct.

>I can log in on the Xfinity website in a browser (on my phone).

>The error is independent of device (we get the same error on my Android phone and my wife's iPhone)

> The error is independent of the account used to log in (both my account and my wife's account give the same error)

> I have tried uninstalling and reinstalling the app

> I have cleared the data for the app on my device

> I have cleared all saved/cached data associated with Xfinity websites on my browser

Nothing seems to be working... Maybe it's an issue on Xfinity's end. 

In either case, I need to get this fixed as I cannot set up our new Xfinity modem without the app (the live chat agent was unable to do it remotely).