AT&T Directs iPhone 18 Pro Max Users to iOS 27.0.1 to Fix SOS Mode Bug

A connectivity glitch has cut off calls, data, and emergency 911 access for some flagship phone owners on AT&T's network.

By The Company WireOctober 2, 2026 at 7:40 PM UTC3 min read

AT&T — AT&T Directs iPhone 18 Pro Max Users to iOS 27.0.1 to Fix SOS Mode Bug. Photo: ZDNET.

AT&T is advising owners of Apple's flagship iPhone 18 Pro Max to immediately install iOS 27.0.1 after a connectivity glitch left some subscribers unable to place calls, send texts, use cellular data, or reach 911 emergency services, according to a report by ZDNET (https://www.zdnet.com/tech/iphone-18-pro-max-att-call-text-sos-issue-update-fix/).

The connectivity problems began following the launch of the iPhone 18 series last week. Impacted devices randomly drop into emergency SOS mode, cutting off cellular network registration even as local Wi-Fi connections continue to function normally.

The issue appears isolated exclusively to the iPhone 18 Pro Max and has not affected other models in the iPhone 18 lineup. While neither company has confirmed a technical root cause, the flagship handset utilizes a Qualcomm modem, whereas standard iPhone 18 variants feature Apple's proprietary C2 modem.

In response, AT&T initiated a text message alert campaign directly to iPhone 18 Pro Max customers, advising them to update immediately via Settings > General > Software Update. Apple released iOS 27.0.1 to fix system freezing, Face ID glitches, and other minor bugs, though the update's official release notes do not mention AT&T or cellular modem performance.

While user reports on support forums and Reddit indicate that installing iOS 27.0.1 restores network service for some owners, it has not resolved the connectivity failure in every case.

In a statement to ZDNET, an AT&T representative said: "Apple has released a software update to address an issue that may affect calls, data, texts and 911 calls on a small number of Apple iPhone 18 Pro Max phones. AT&T customers with an iPhone 18 Pro Max should update their phones now to the latest available software. Our top priority is ensuring customers can stay connected when they need it most, and we are working with Apple to make it right." AT&T noted that subscribers who still experience issues should visit an Apple Store or AT&T retail location for additional support.