Apple Confirms AT&T-Specific Glitch Forces Free Replacements for iPhone 18 Pro Max

Key points

• Apple confirmed a bug affecting a 'small number' of iPhone 18 Pro Max users on AT&T networks in the US, causing total loss of cellular service.
• Affected devices display an 'SOS' symbol in the status bar and cannot make calls, send texts, or use 4G/5G data, including emergency 911 calls.
• Apple released iOS 27.0.1 and a carrier settings update to prevent the issue from occurring on other devices, but these updates do not fix phones that have already lost service.
• Users whose phones have already failed must contact Apple Support or AT&T to receive a free hardware replacement; software updates or restores will not resolve the issue.
• The issue is isolated to the iPhone 18 Pro Max, which uses a Qualcomm Snapdragon X80 modem in the US, while the iPhone 18 Pro uses Apple's C2 modem and is unaffected.
• AT&T sent text messages to affected customers urging them to update to iOS 27.0.1 immediately, though some users report the update did not resolve their existing connectivity problems.

Background

The iPhone 18 Pro Max launched in September 2026 at a starting price of $1,299, replacing the previous iPhone 17 Pro Max. It is the only US model in the current lineup to use a Qualcomm modem, as Apple has been transitioning to its own C2 modem technology. The iPhone 18 Pro, which uses the C2 modem, is not affected by this issue. This follows previous reports of Apple moving away from third-party modem providers, with the Qualcomm contract set to expire this year.

How outlets are covering it

Engadget and 9to5Mac report that Apple confirmed the issue affects a 'small number' of users and that the iOS 27.0.1 update and carrier settings patch are intended to prevent future occurrences, not fix existing failures. CNET notes that MacRumors estimates thousands of customers have been affected, and that some users report the iOS 27.0.1 update alone did not fix the problem, nor did upgrading to the iOS 27.2 public beta. PCMag highlights that AT&T sent text messages to customers urging immediate updates, and that some users had to visit Apple Stores to get replacement units. All sources agree that the issue is isolated to the iPhone 18 Pro Max on AT&T networks, with no similar reports from T-Mobile, Verizon, or Google Fi users. CNET and PCMag note that it is unclear whether the issue is related to the Qualcomm modem, as the iPhone 18 Pro Max is the only US model using it, while the iPhone 18 Pro uses Apple's C2 modem and is unaffected.

Why it matters

This issue affects a core function of a flagship smartphone—making calls and accessing data—and requires a hardware replacement for affected users, which is a significant inconvenience and potential cost if not covered. It also raises questions about the reliability of Apple's transition to its own modem technology, as the issue is isolated to the model using a Qualcomm modem. The fact that the software update does not fix the problem for already-affected users suggests a deeper hardware or firmware issue that cannot be resolved remotely.

What to watch

Apple and AT&T are working to resolve the issue for affected users through hardware replacements. The carrier settings update is expected to roll out over the next two weeks, and users can manually trigger it via Settings > General > About. Apple and AT&T have not explained the root cause of the issue, and it is unclear whether the problem is related to the Qualcomm modem or other factors. Users who have already lost service should contact Apple Support or AT&T to request a replacement.