In a text message sent to customers today, AT&T acknowledged that some iPhone 18 Pro Max devices on its network are experiencing cellular issues.
AT&T said that customers should immediately update to iOS 27.0.1, despite the fact that many affected users have said that the update does not resolve the issues. There are now at least thousands of users that have experienced this problem, according to discussion topics across the Apple Support Community, Reddit, and MacRumors Forums.
Here is what the text message says:
Hi, it's AT&T. Action needed: An important Apple software update for your iPhone 18 Pro Max is available. Some phones may be unable to complete calls/text/data, including to 911. Update to iOS 27.0.1 immediately — Settings > General > Software Update. Please contact AT&T or Apple if you have questions.
Apple's release notes for iOS 27.0.1 did not mention a fix for AT&T cellular issues. Rather, the update fixed a Face ID issue on the iPhone 18 Pro models.
As we reported last week, affected iPhone 18 Pro Max users are unable to connect to the AT&T network for phone calls, text messages, or data either persistently or intermittently, and their devices typically enter SOS mode as a result. The underlying cause has not been confirmed, and Apple has yet to publicly comment on the matter.
Notably, the U.S. version of the iPhone 18 Pro Max is the only new iPhone unveiled last month that is equipped with a Qualcomm cellular modem. The smaller iPhone 18 Pro and the iPhone Duo are equipped with Apple's C2 modem worldwide, as is the iPhone 18 Pro Max in all other countries. However, it is unclear if this is a contributing factor.
If a software issue is identified, then another update such as iOS 27.0.2 may be required. If there is a hardware issue, though, then this would obviously be a much bigger problem. We will provide further updates as new information becomes available.
