AT&T Internet DirecTV Bundle, Can't Manage/Log In To DirecTV

We have the AT&T Internet DirecTV Bundle. We're in an apartment and connect our TV box to our router (we may have DirecTV stream, but our bundle doesn't include stream in its titling nor in our billing as far as we can tell, more on that below)

We want to manage our DirecTV subscription - i.e. add premium channels, activate 4K, etc.

We can log into att.com and our bill is paid through AT&T.

There's no DirecTV administration or even mention in our account. 

There never was, and we were never sent any notification to also set up a separate DirecTV login, so we don't have one for that site at all. Didn't need it as we haven't wanted to change anything...

Going to TV or Bundles options in the menu on att.com's account management area causes a redirect to DirecTV.com

Attempting to log in there with our account credentials (which automatically register there like they do on att.com) triggers an error along the lines of:

"It appears you've tried to log in with your AT&T credentials, we'll redirect you to the login page and you can enter your directv credentials"

Thinking we may have set it up and forgotten, or at least had our email registered to DirecTV.com, I attempted to reset the password through DirecTV. 

The email address we use for all our utilities worked and received an authentication code, so I reset the password and hit proceed to account.

I get the "you've used your at&t credentials to log in we'll redirect you..." Error.

I go back to att.com and had to log in with the password I'd just entered through the DirecTV.com reset system to get into AT&T

(More on DirecTV stream here:) Trying to access anything related to DirecTV stream leads to DirecTV.com and the same feedback loop.

Part of the system seems to think they're the same credentials and part of the system does not. 

We just want to upgrade our TV service... Help, please.