Full Breakdown
AT&T Warns iPhone 18 Pro Max Users of Ongoing Cellular Problems
By Drooid · · How we work
AT&T Alerts Customers to Immediate Software Update
AT&T sent a text message to owners of the iPhone 18 Pro Max on its network, instructing them to install iOS 27.0.1 without delay. The carrier warned that, without the update, phones may be unable to complete calls, texts, data sessions, or even emergency calls to 911, and could repeatedly enter SOS mode.
Scope and Symptoms Reported by Users
Discussion threads on the Apple Support Community, Reddit, and MacRumors forums indicate that at least thousands of U.S. iPhone 18 Pro Max owners have experienced either persistent or intermittent loss of cellular service after the device’s launch. Many users report that installing iOS 27.0.1 does not resolve the problem, despite AT&T’s recommendation. The issue appears limited to the U.S. version of the iPhone 18 Pro Max, which is the only model equipped with a Qualcomm cellular modem; the iPhone 18 Pro, iPhone Duo, and international iPhone 18 Pro Max units use Apple’s C2 modem.
Carrier and Manufacturer Responses
AT&T’s message emphasized the urgency of the iOS 27.0.1 update but did not provide technical details about the root cause. Apple’s release notes for iOS 27.0.1 mention a fix for a Face ID problem on the iPhone 18 Pro series, with no reference to the AT&T cellular issue. Apple has not issued a public comment confirming whether the problem is software-related or hardware-related.
Potential Next Steps
If a software defect is confirmed, AT&T indicated that a subsequent update—potentially iOS 27.0.2—could be required; the possibility of such an update was noted on May 2. Should the issue stem from the Qualcomm modem hardware, the resolution would likely involve more extensive repairs or replacements, representing a larger operational challenge for both carrier and manufacturer.