My phone won't automatically switch from 3g to 4 when I enter an area . My son's s4 does however it has sprint spark and mine does not. Also if I loose service , when I reenter a service area it doesnt recognize it until i uncheck mobile data and recheck it. Also doesn't always have reception when my families other sprint pones do. Any ideas as to what I can do? I have tried prl updates and such. Thanks