We have two s5's one gets 4G service just fine the other will not get it. You turn the phone off and back on and you get 4G for about ten seconds and then it's back to 3g, the other phone it steadily on 4G. We have traveled from SC to TN and had the same problem all the way there and back, doesn't matter if you're inside or outside. Did a factory restore and that did nothing to help.
