I am in a solid 3G/LTE area, and my new iPad will only show at most 4 bars of signal. Usually between 2 and 3 bars. I have seen a full 5 bars once when I was outside. Just sitting in my house it will constantly go from one to 4 bars back and fourth. I went too the genius bar and they said its getting signal so it's working fine. I've tried a full restore, with no luck Any tips?