Apple released iOS 27.0.1 earlier this week after launching iOS 27 in September. The update fixes a Face ID-related reboot issue on the iPhone 18 Pro and iPhone 18 Pro Max. However, AT&T is now telling some customers to install the update immediately. The carrier says it also addresses a serious network issue affecting the iPhone 18 Pro Max.
According to an automated AT&T message, the issue can prevent an iPhone 18 Pro Max from completing calls, texts, and data sessions. The message also warns that emergency calls to 911 could be affected.
There is one problem with AT&T’s claim. Early reports from several AT&T users suggest that iOS 27.0.1 does not resolve the network issue. Affected users still cannot connect to the carrier’s network after installing the update.
The problem appears to affect calls, texts, and mobile data. Users also report seeing “SOS” in the status bar of their iPhone 18 Pro Max. Not every iPhone 18 Pro Max on AT&T appears to be affected. Still, reports suggest the issue is widespread among some users on the carrier’s network.
The iPhone 18 Pro does not seem to have the same problem. One possible reason is the different modem hardware used in the two models. The iPhone 18 Pro Max reportedly uses a Qualcomm modem. Meanwhile, the iPhone 18 Pro uses Apple’s own C2 modem.
For now, affected AT&T customers may need to wait for another fix. Apple and AT&T have yet to provide a clear explanation for the ongoing network problem.
