Some iPhone 18 Pro Max owners on AT&T have lost cellular service for good, and the only fix is a brand new phone.
Apple confirmed that a small number of iPhone 18 Pro Max units on AT&T's network have lost cellular service entirely, killing calls, texts, and data. The company shipped iOS 27.0.1 earlier this week and pushed an AT&T carrier settings update today, both meant to stop new cases from happening; the carrier update rolls out automatically to AT&T customers over the next 14 days. For phones already affected, though, there is no software fix. Apple says those units need a full replacement, free of charge, available through Apple Stores, the Genius Bar, Apple Support, or an AT&T location.
Apple calls this a small number of devices, but thousands of users have complained across Apple's own support forums, which is a gap worth noting. The company also has not explained what is actually failing. US iPhone 18 Pro Max units run Qualcomm's Snapdragon X80 modem, while the same phone sold elsewhere uses Apple's own C2 modem, and Apple did not say whether that split explains why only AT&T, and only in the US, is seeing this problem.
A bug serious enough to require swapping hardware rather than patching software is a bigger deal than a routine carrier glitch, and it lands right as Apple tries to wean its phones off Qualcomm modems for good.