Apple Confirms AT&T Network Bug on iPhone 18 Pro Max, Some Affected Units Need Replacement

The acknowledgment follows a number of complaints about network issues on the device. Apple told 9to5Mac the problem affects only a "small number" of iPhone 18 Pro Max users on AT&T's network and may cause a device to lose service and be unable to make calls. The company said it released iOS 27.0.1 earlier this week and was issuing a carrier settings update, and it strongly encouraged all iPhone 18 Pro Max users to update now.

"We have identified an issue affecting a small number of iPhone 18 Pro Max users on the AT&T network that may cause a device to lose service and be unable to make calls," Apple said in the statement to 9to5Mac. "We released iOS 27.0.1 earlier this week and strongly encourage all iPhone 18 Pro Max users to update now, and are also issuing a carrier settings update today. These updates together are meant to help prevent this issue from occurring."

The symptoms are visible on affected devices. An iPhone 18 Pro Max with the bug shows the "SOS" symbol in the status bar instead of signal bars, and calls, text messages and data over 4G or 5G stop working, according to the report. Not every iPhone 18 Pro Max owner using AT&T has been affected, and Apple has not said how many users or devices are involved.

For users whose phones still have service, the fix is preventive. Apple advises updating to iOS 27.0.1 as soon as possible by going to Settings, then General, then Software Update, and looking for the latest version. Users should also check whether they have the latest carrier settings by going to Settings, then General, and tapping About to trigger the update. If no pop-up about a carrier settings update appears, the device probably already has the latest version, according to the report.

If an iPhone has already lost its cellular signal, a software update or restore will not work. Those users should contact Apple Support or AT&T to request a phone replacement, Apple told 9to5Mac. The iPhone 18 Pro Max is the only model sold in the United States that uses a Qualcomm modem instead of Apple's own modem, according to the report, but it is unclear whether there is any direct connection between that hardware choice and the bug.

Apple's acknowledgment came after complaints about network issues affecting the device. The report said the issue appears to have affected only AT&T users in the US. The statement reported by 9to5Mac did not address whether other carriers or iPhone models are affected.