09/2019 Yahoo Login Redirects to ATT Forgotten PW

I've had a yahoo email address for about 20 years. I've also had three ATT.net email addresses associated with home internet in the past, and I forget whether they were ever linked to my one yahoo email address. Through Aug 2019, I had one-step login on my Yahoo cellphone app, and if needed, Yahoo would ping my cell phone to allow me to authorize sign-in on new devices. Everything was working beautifully on my cell phone and on my desktop.

In Sept 2019, my phone died and I got a new cell phone. I tried to download the Yahoo app, but when I typed in my username, it routed me to ATT 'Forgot Password' webpage. I went to Yahoo on my desktop browser (where I was still logged in) to try to go to Account Options and remove the 1-touch and any other Yahoo account verification options, but in order to change my account options, I was forced through a 'verify login' cycle, which again routed me to the 'Forgot ATT PW' page.

I know my yahoo.com password, and I know my ATT.net password, these things should be separate.

Further, I think since my yahoo account was on 1-touch, it's not allowing me to type my password in at all. Now every single browser, phone app, computer that I try to use reroutes my particular yahoo email address to ATT's forgotten password side. On these same browsers, I'm able to login to other yahoo accounts, so the problem is only on my email address. I'd really like to recover this account since it has 20 years' worth of information stored.