[Q] Data won't work after upgrading to NAE via KIES? topic

I have learned all I know about flashing ROM's and rooting phones thanks to all of the helpful people here! I'm running the latest stock NAE, which I found as an automatic download via KIES, on my unlocked sph l720, with the StraightTalk network and AT&T SIM. Everything works great except for the data, it will toggle on, but not actually receive data.
Has anyone else came across this issue and been able to resolve it? Or any advice for a new guy? I'd really appreciate it!

-Adrian