Anyone else on other phones or carriers seeing the same thing? I do not pay for Tethering on my plan and the phone previously told me so, but after updating to 8.1 dev preview, it works just fine.
This was working before 8.1. I've been using tethering ever since I switched over to their 4 user/10GB value plan. I think it has more to do with the fact that AT&T has now bundled tethering in with the package.