Some iPhone 18 Pro Max units are losing cellular connectivity

Apple has confirmed a cellular connectivity issue affecting some iPhone 18 Pro Max units on the US carrier AT&T’s network. If a smartphone has already lost network connectivity, it cannot be restored via software.

Cellular connectivity issue

The glitch leads to a loss of connection to the AT&T network. Affected iPhone 18 Pro Max units enter SOS mode, after which standard calls, SMS, and mobile data stop working.

Apple states that the malfunction has affected a “small number” of users, but the company has not disclosed the exact number of problematic devices.

To prevent the glitch, Apple recommends installing iOS 27.0.1 along with the AT&T carrier settings update. The latter should automatically download to smartphones within 14 days. You can check for it manually in Settings → General → About.

However, the cellular connectivity issue is not explicitly mentioned in the iOS 27.0.1 changelog published by Apple. The company explains that it is the combination of the new iOS version and the carrier settings that should prevent the malfunction from occurring.

When an iPhone replacement is required

Updates do not restore functionality to smartphones where the issue has already manifested. For owners of such iPhone 18 Pro Max units, Apple recommends contacting Apple or AT&T support or visiting a store for a hardware replacement.

Apple has not yet announced a public mass recall. This only concerns the replacement of specific smartphones already affected by the confirmed glitch.

The US version of the iPhone 18 Pro Max uses a Qualcomm modem, while the iPhone 18 Pro and international versions of the iPhone 18 Pro Max are equipped with the Apple C2 modem. However, Apple has not identified the modem as the cause of the malfunction, so there is currently no basis to link the glitch to Qualcomm.

There are currently no reports of a similar issue with the iPhone 18 Pro Max outside the United States.