In a statement to 9to5Mac, Apple acknowledged that some iPhone 18 Pro Max users on the AT&T network have lost service and can’t make calls. Chance Miller quotes Apple as saying:
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. 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.
According to Apple, affected iPhones will need a hardware replacement, which is alarming—it’s hard to imagine what could cause a hardware failure like this. The problem likely relates to the iPhone 18 Pro Max relying on a Qualcomm modem, while the iPhone 18 Pro uses Apple’s new C2 wireless chip. However, Apple says installing iOS 27.0.1 and a carrier settings update should prevent the problem from occurring in the first place. The carrier settings update will install automatically within the next 14 days, though you can get it sooner by going to Settings > General > About. It’s unclear whether the problem affects only direct AT&T subscribers or also iPhone 18 Pro Max users on MVNOs that use AT&T’s network, such as US Mobile’s Dark Star and Cricket Wireless.
