Switched from AT&T a few weeks ago. When driving to work in the mountains (near Yosemite, CA), I drive through an area where I lose cell phone coverage on/off again for about 20 minutes. Once I arrive in the city with reception (Mariposa) or coming back (Ahwahnee/Oakhurst), randomly the cell phone does not reconnect to the network. I pull my phone out of my pocket and it shows "no service" (brand new phone, Samsung S21 Ultra). I have actually tried this with 2 different Samsung S21 Ultras, one that is "blank" - brand new, nothing moved over from a previous phone - and another one that has all my stuff copied. Both phones behave the same way.
There is a solution - turn on "airplane mode", wait 15 seconds, and then switch airplane mode off. It grabs the signal with no issue. But unless I want to restart the phone, or doing the airplane on/off trick, the phone just sits there with no connection. This is really frustrating because I have to keep checking my phone to make sure I have service, and I can miss important calls/texts. Since this is obviously during a commute, I would also have to do this WHILE DRIVING. This never happened with AT&T. I have tried resetting the network connections, but that did not make a difference. I asked other users in the area and they said they too have this issue, but just deal with it.
The root of the problem seems to revolve around the phone not automatically reconnecting after it loses service. The phone doesn't just randomly lose service - it goes through an area with no service, and then just never reconnects.
I'm not sure why this only happens on Verizon's network - and, frustratingly, why it is not consistent. At first it seemed like the problem was only in the arrival city (Mariposa), but now it actually happens both ways... but it won't happen every day or every time I make the trip.