Short version ... they have made some changes to the website that broke a few functions.
They (Hughesnet) are aware of the problem and it will be addressed in due course.
In Gabe's breakage prevented him from using a Direct Express Social Security debit card to pay his bill as he had in the past.
In my case it prevented me from making an advance payment.
The "solution" in the short term is to use the "old" website and click on its "view/pay without login".
That page can be found here:
The link for the view/pay without login is highlighted below:
The issue will get resolved .. it is likely they have their hands full at the moment with the J-2 launch and setup.