I did hard reset and this fixed my internet problems. BTW, have to delete the proxy url (216.155.165.050), which TMo gave me, otherwise https does not work. So just 'fast.t-mobile.com' (presence or absence of user name does not make any difference). However whatever I do, I cannot get Internet Sharing. I spoke to ATT, they say it is TMo issue. Talk to them. But of course, TMo does not guarantee anything for not TMo phone... So what else could be the difference? For some folks it works, for some it does not. It did work for me but only once. I wonder, does anyone know if this could depend on the TMo data plan? I have 2GB (and then it goes from LTE to Edge)