I did this and it switched back to 3G, and also can surf and talk.
Is 4G supposed to work if u call ##78...and edit the option.
Also, another problem I'm having is that sometimes I just lose internet overall. Where it's supposed to say 1X, 3G or 4G there's nothing there so when I go online it doesn't work. And after a while it comes back. When I put airplane mode on and then off it fixes it but temporarily only. wtf it's pissing me off. And even GPS has been messed up.
I don't wanna return the phone cause it's hacked and customized the way I like it.