My phone connects with full service then drops LTE, goes to 0 bars, then no service.

When I turn my phone on or reconnect to the network from airplane mode my iPhone 6s momentary phone shows full bars of service of Verizon LTE, then the LTE dissapears , then I have 1 or zero bars of Verizon service, then no service. Problem stated with this as a new phone in May 2016. Now running IOS 10.0.2 If I turn my roaming off in Steeings, Cellular, Roaming (Off) I only get one bar of service sometimes If I can stay connected to the tower.

I've spent five months and over 40 hours on the phone with senior level Apple and Verizon technicians and still have no resolution to this problem. We have replaced some cards and iphones numerous times. This is a software problem problem with Apple. Verizon Technical support states that the phone does not fully connect with their network. My SIM card works fine in iPhone 6 and other nonApple Verizon phones and show full bars of service at the same location.

If I turn the roaming off it shows that I have signal sometimes but only one or zero bars and experienced lots of dropped calls and not able to make calls or even try to connect to send a call after pressing the Send Button.

In my Settings menu it does not show Carrier underneath Cellular Settings option. Once in a while it will show momentarily. In Settings, General, About, Carrier is Verizion version 25.1

I Still have no resolution to this problem! Verizon said that are also seeing the same probem with the Iphone7. Local Verizon Storea and customers have replace dozens of phones with the same problem. Customers are frustrated and replace their iphones with a non Apple format Phone.