Xfinity tv provider login page not loading for ESPN on Fire TV/Stick

Suddenly this week every time I open the ESPN app on my fire TV and on my TV's with fire sticks, the app ask me to choose my TV provider.  I choose Xfinity, type in my username and then then hit NEXT but the menu won't go to the next screen where I can put in my password.  The app works fine on my Roku tv.  Any ideas on why the fire sticks/fire TV are not working?  Any solutions to this problem?