All Verizon 4G is LTE
my indicator says 4G it does not say LTE
admittedly it works better when there is some signal strong enough to show on the phone
but I have seen a 1 or 2 bar 4G signal when in the sleek, that was NO 4G without the sleek, my rational is the tower was too far for the phone to send to even if it was detecting the weak signal
remember the booster is two-way, not just receive but also sending a stronger signal from a larger antenna, even the rubber ducky antenna is larger than the one inside the phone
but there has to be some signal for the sleek to boost
im thinking there is no 4G signal in your area
btw that also includes the antenna MUST be tuned for 4g Verizon band
which is the 700mhz for the LTE