Apple confirmed a cellular service issue affecting a small number of iPhone 18 Pro Max users on the AT&T network, causing devices to lose calls, texts, and data. The company released iOS 27.0.1 and an AT&T carrier settings update to prevent further impact. However, affected devices cannot be restored via software and must be replaced entirely.
Apple advises users to contact Apple Support, AT&T, or visit an Apple Store or AT&T location for a free replacement. The issue has only been observed on AT&T; no other carriers or iPhone models are affected. U.S. models use Qualcomm's Snapdragon X80 modem, while other regions use Apple's C2 modem — it's unclear if this difference plays a role. Apple has not disclosed the root cause, and while an Apple Service Program is possible, stores are currently handling replacements directly.
Source: MacRumors · Summarized by HeadlinesBriefing