I have a MiFi4510L that constantly drops to or uses a 3G signal over a 4g signal. This occurs even though the 4g signal has a lower db then the 3g signal. If it starts off at 4g and drops to 3g it will not go back to 4g unless I turn the unit off and back on. Verizon's on;y response is that I live in an extended coverage area for 4g. This makes no sense if the 4G signal is stronger the unit should pick it up. Any and all help appreciated. Also I am running an external window antenna on my unit.