I'm here in Phoenix and both my phone and my wife's weren't showing "LTE", only "4G". Called AT&T, spoke with tech support and they confirmed that the phone was not connecting to the LTE network.
They unregistered my phone from the LTE service, then reregistered it, had me reset the network settings and about 10 minutes later...LTE was live!
The tech support lady said they have had a lot of calls about this today from new iPhone owners.
They unregistered my phone from the LTE service, then reregistered it, had me reset the network settings and about 10 minutes later...LTE was live!

The tech support lady said they have had a lot of calls about this today from new iPhone owners.