We installed 14.3 yesterday on our problem iPhone X's. It did not help. The phone is useless as a phone.

I'm following this closely. We have a pair of iphone X that have had an issue where previously 3 bars of service are now either 1 or none with calls dropping a minute or two into the call. We're with verizon and have called them multiple times, had a call with Apple where the devices were reset. The last course of action was that we bought a network extender and installed it yesterday. After we activated it, by calling Verizon tech support, there was no improvement in cell service. The ticket was bumped up two tiers and is currently in the advanced technical support and in a pending status. They are going to attempt to get the network extender to produce better signal. This really seems like it HAS to be an iphone IOS issue. I'm actually just the administrator of the business account, the two users with the problem happen to be the Owner of the company and his wife. It's not great to have the owners phones not work. This has been going on for weeks with noone admitting any fault or errors. I'm waiting to hear if an update to 14.3 helps, and also waiting to find out if Verizon can magically make the network extender (that we purchases through Verizon and wasnt given to us for free) work.