Default [Q] tethering, cm11 firefox doesn't work everything else does

I have T-Mobile and I am allowed tethering. I am running cm11 on both my phone and my wifi-only tablet. If I use chrome on the tablet I can browse all I want, all web apps work, Email works. Firefox on the tablet redirects to my T-Mobile account page.

This used to work with the stock nexus galaxy tab ROMs.

Any ideas why ff is doing this?