If you've got AT&T fiber via Sonic, give them a call and ask them to escalate the issue. The people on the phone know about the issue, take you seriously, and the more people complaining the more pressure they'll put on AT&T, I expect.
I have done this earlier today and it is exactly as you say. All they can do is file another ticket with AT&T, but multiple tickets coming to one ISP from another ISP mean more than calls or tweets to the AT&T customer support line, so here's hoping! Some people on Twitter report this problem going back all the way to November. Glad it's finally getting attention tonight.