AT&T has acknowledged cellular connectivity problems affecting the iPhone 18 Pro Max on its network, first reported by MacRumors. The carrier sent a text message to customers advising them to install iOS 27.0.1, warning that some devices may be unable to complete calls, send texts, or access data — including calls to 911.
However, many users report that the update does not resolve the issue, and Apple has not publicly commented. Apple’s official release notes for iOS 27.0.1 mention a Face ID fix for iPhone 18 Pro models but say nothing about cellular connectivity. The problem appears to involve iPhone 18 Pro Max devices failing to connect to AT&T’s network, sometimes entering SOS mode.
The iPhone 18 Pro Max was released last month. In the U.S., it is the only new iPhone model equipped with a Qualcomm cellular modem; the iPhone 18 Pro and iPhone Duo use Apple’s C2 modem, as does the iPhone 18 Pro Max outside the U.S. Whether that hardware difference is a factor is unclear.
According to AppleInsider, the problem is believed to affect a relatively small number of users. One reader, Rod Santiano, said Apple tested his phone and found nothing wrong but replaced it anyway, and the replacement works. “We’re still using our iPhone 18s as glorified iPods,” he said.
It remains unknown whether a future iOS update will truly resolve the issue or if hardware is involved.