GoKawiilApple confirms iPhone 18 Pro Max cellular bug on AT&T, offers hardware replacement
Apple confirmed that a small number of iPhone 18 Pro Max devices on AT&T's network are losing cellular service, showing 'SOS' instead of a signal. The company released iOS 27.0.1 and a carrier settings update to prevent the issue from occurring, but says devices that already lost service will need a hardware replacement through Apple Support, AT&T, or in-store visits.