I've had Verizon Wireless for well over a decade and in my previous residence had no problems with signal. Yet when I moved to my new home in Knoxville two years ago, I've been unable to get much of a signal, even outdoors. Running a field test outdoors gives me < -120 dB signal - meaning not only is my LTE unusable indoors, but it's often barely usable outdoors (frequently dropped calls, failure to dial). Worse, the signal quality is so poor that I am unable to even make use of a cell booster system - there's not enough signal to amplify.
The Verizon coverage map shows our location squarely in the middle of a 4G coverage area, and yet the signal here is next to non-existent. I have to wonder whether there is adequate tower coverage here given the terrain; going about a mile north, I can get perfectly fine signal.
I can use WiFi calling indoors, but this is not a replacement, especially when the power goes out (which happens more often than I'd like). Several of my neighbors have also reported signal quality issues in this area.