Apple confirms cellular failure for some iPhone 18 Pro Max units on AT&T’s network

Apple has confirmed a cellular connectivity failure affecting some iPhone 18 Pro Max owners who use the network of the US carrier AT&T. The company gave its statement to 9to5Mac on October 2, 2026. Affected users lose signal, "SOS" lights up in the status bar, and the phone stops making calls, sending messages, and getting online.

Apple refers to a "small number" of such units and stresses that the problem has not affected all iPhone 18 Pro Max users on AT&T's network. The company said it identified an issue that can cause a device to lose service and be unable to make calls, and released updates meant to keep it from recurring in other units. Apple does not name the cause of the failure.

Two things are involved here: iOS 27.0.1, released earlier the same week, and a carrier settings update being distributed on October 2. The carrier settings update should download automatically within 14 days. Owners can speed up the process manually: "Settings," the "General" section, the "About" item.

An important caveat: these updates prevent the problem from appearing in other devices, but they do not restore connectivity to devices where it has already disappeared. According to Apple, such phones need a hardware replacement — that is, the device itself.

Owners of affected iPhone 18 Pro Max units are advised to contact Apple or AT&T support, or to visit an Apple Store or an AT&T store.

A curious detail concerns the modems. In the US, the iPhone 18 Pro Max is still supplied with a Qualcomm modem, while the iPhone 18 Pro has Apple's own C2 modem. It is precisely the model with the Apple C2 modem that does not suffer from these AT&T problems.

Image: NetworkerTurbo165 Public domain

Translation editors: Соловьев В., Пеков А.