In a statement shared with MacRumors on Friday, Apple said that iPhone 18 Pro Max users who have experienced an issue where AT&T cellular service does not work will need to have the device replaced , as the issue apparently cannot be fixed with a software update once it has occurred. That is a big deal, as it hints at hardware failure, but we lack details since Apple and AT&T have yet to disclose the underlying cause of the issue. A spokesperson for AT&T directed us to Apple, which has yet to respond to our latest request for comment. It is possible that Apple is still investigating the issue, but so far our follow-up questions have been met with radio silence (pun intended). 1 and an AT&T carrier settings update released last week "are meant to help prevent this issue from occurring," so iPhone 18 Pro Max users who have not experienced this issue should ensure that both of these updates are installed immediately to avoid potential future impacts. 1, open the Settings app on your iPhone and tap General → Software Update. The carrier settings update for the iPhone 18 Pro Max will automatically download for AT&T users within the next 14 days, according to Apple. To manually trigger the update, users can open the Settings app and tap General → About. Apple said it has only observed this issue with iPhone 18 Pro Max users on the AT&T network. No other iPhone models or carriers are known to be impacted.