Where the signal bars should be in the status bar, there's just an "SOS" label instead — that's what some iPhone 18 Pro Max owners have been seeing on their screens these past few days. No calls, no texts, no 4G or 5G data at all. According to 9to5Mac, Apple has confirmed this is a real hardware issue, currently limited to users on AT&T's network in the US.
In a statement to 9to5Mac, Apple said: "We've identified an issue affecting a small number of iPhone 18 Pro Max users on AT&T's network that can cause the device to lose signal and become unable to make calls. We released iOS 27.0.1 earlier this week and strongly recommend all iPhone 18 Pro Max users update immediately. We're also rolling out a carrier settings update today. Together, these two updates are designed to prevent this issue from occurring."
The key word here is "prevent" — meaning the patch only works for devices that haven't already run into the problem. For phones that have already completely lost signal, a software update or restore won't fix it. Apple says affected users will need to contact Apple Support or AT&T for a hardware replacement.







