I use an iPhone SE. Within the past month or two, LTE signal strength in the 35808 & 35898 zip codes has become horrendous. Previously, I could maintain a solid 4-5 bars of LTE service in the -90 to -80 dBm range. Now, I'm lucky if it drops below -100dBm, and it's usually around -110dBm, which is practically unusable for data. What is going on?