DIRECTV / AT&T Login error

Can’t log in to the DirecTV app on my iPhone. Keep receiving a 201 error. Spent 90 mins with AT&T tech support but they were zero help. No matter how many times I change the password or user name I still receive the same error. When I go into settings the TV provider is set to DirecTV, but is greyed out and won’t let me make any changes. I was able to log in to the DIRECTV app by using my wife’s cell phone. This question has been asked by many but has not yet been answered, as far as I can tell?