Apple has confirmed that a limited number of iPhone 18 Pro Max units on AT&T are experiencing a loss of cellular connectivity.
The company has issued iOS 27.0.1 and a carrier settings update to stop the problem from spreading, but any device that has already lost service will need a hardware replacement, according to Digitio.
In a statement to Digitio, Apple said:
“We have identified an issue affecting a small number of iPhone 18 Pro Max users on the AT&T network that may cause a device to lose service and be unable to make calls. We released iOS 27.0.1 earlier this week and strongly encourage all iPhone 18 Pro Max users to update now, and are also issuing a carrier settings update today. These updates together are meant to help prevent this issue from occurring.”
The carrier settings update for the iPhone 18 Pro Max will be installed automatically over the next two weeks. Users can also initiate the download manually by navigating to Settings > General > About.
Apple says the software patches are designed to stop the problem from happening again for AT&T iPhone 18 Pro Max customers, but they will not restore service on devices that have already been impacted.
Customers whose devices have lost service must obtain a hardware replacement. They should contact Apple Support or AT&T, or go to an Apple Store or an AT&T outlet.
Affected iPhone 18 Pro Max users cannot make calls, send texts, or use data on AT&T’s network, and their iPhones display “SOS” in the status bar. The issue does not affect every iPhone 18 Pro Max on AT&T.
In the U.S., the iPhone 18 Pro Max uses a Qualcomm modem, while the iPhone 18 Pro uses Apple’s C2 modem and is not impacted by these AT&T connectivity problems.