AT&T Thanks Error Code 401 "No Accounts Found"

I've been looking through this forum trying to find a solution to this and nothing that I've found has resolved this issue for me.

Here are some of the things I've tried:

Uninstalled the app/reinstalled, attempted to login.

Unlinked the account/relink the account, attempted to login.

Restarted my phone, attempted to login.

Visited the AT&T Thanks website on mobile and desktop, attempted to login.

I am at a lost here.

My account is eligible for AT&T Thanks and yet I am unable to access it.

Please help.