So I am running version 4.5.4.1A and I actually have 2 phones and one works. on the on that doesn’t work I checked every setting and made sure they’re the same. I checked the APN and they’re the same as well. Also when i switch the SIM cards the broken one starts working and the working one stops working. I have AT&T and I have gone to the store and have gotten a new SIM card for it as well but still the same problem. Any Idea on what is wrong? Also if this helps at all I can still receive text’s and calls with the broken one, I just can’t access the internet or any apps that require it.