How to get credentials to work for service authentication of TV provider

Have used the "link your TV provider" service to use on my laptop, appletv, work PC, iPhone, iPad, Samsung Android phone without any issue for years. Starting two weeks ago i am not able to get ANY service to authenticate. Each gives some form of "this channel is not included in your plan". I am a U Verse 450 customer and pay just shy of $400/mo for all of my AT&T services. I have spent a combined 14hrs on the phone, over 5 calls to support to explain what it happening. I have let them see my phone screen and they have seen firsthand what is happening and have no answer to how / why this is happening. Many of the support people state the issue is with the content provider until remind them it is ALL channels and they all say "this channel is not in your service plan". The last rep on Friday said "i dont know what to tell you, its supposed to work, but my senior technical support is telling me to "tell you to contact ESPN, ABC, NBC, CBS, TNN, TNT, MTV and on and on and the problem is on their side". Hard to believe.

The user name (email / user name with att.net / pw) that i have always used and is the same that i use to sign onto my AT&T account portal is the one i have always used on the "link your provider". It does not say "Credentials are incorrect". Have tried Wi-Fi only, Cellular only, different cities, different devices, and the same results.

How do i get in touch with someone at AT&T that values my $400/mo bill for the last 7 yrs before i have to cancel and try something entirely different to simply be able to watch the channels i pay for when I am traveling? I travel every week and am only home on the weekends, so this is really often my only way to see alot of the things that are of interest to me.

Seems like a service description or billing code or corrupt services identifier assigned to my account is telling the content providers that i don't pay for these channels. It is easy to show or replicate. I even told them to use my user name and pw so they could witness it themselves.

I am just at the end of my rope and surely this is fixable without me having to rip 6 STB and modem out and start with some new internet provider and just go only streaming.