After seeing Sal's note and seeing I had 3G too, I called Verizon tech support. They figured out my phone was set to Global mode rather than LTE only, and after a reboot, 4G-LTE came up, so they were convinced that they fixed the problem. I'm not! It has been on Global mode for over 6 months and I see 4G plenty. This area has too many weak spots, especially the influx of people we get on weekends.
The *228 fix that rscalso mentions used to work, but I've heard that with 4G-LTE, it is no longer needed. It probably can't hurt. When I just tried it, I got a message saying "A Verizon Wireless SIM card has activated your service and updated your phone's roaming capabilities". Yet, here I sit with 1 bar (well, two if you want to count the cabinet above the stove
)