Apple advises iPhone 18 Pro Max users on AT&T to install updates amid connectivity issue

Apple has confirmed that a limited number of iPhone 18 Pro Max units on the AT&T network can lose cellular connectivity, displaying only an SOS icon and preventing calls, including emergency calls. The company says the problem is a hardware defect and will replace affected devices at no charge under warranty.

Apple urges all iPhone 18 Pro Max owners to install iOS 27.0.1 and a carrier settings update released this week to prevent the issue. The software update is available through Settings > General > Software Update, while the carrier update can be triggered manually via Settings > General > About and should install automatically within two weeks.

"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," Apple told 9to5Mac.

If a device is already unable to connect to cellular service, Apple states that the updates cannot restore functionality and the only remedy is a hardware replacement through Apple or AT&T. The discrepancy between the Pro Max and the standard Pro model may be related to the former’s Qualcomm modem, whereas the latter uses Apple’s own C2 modem, though Apple has not confirmed a specific cause.