Some US iPhone 18 Pro Max users are reporting issues with AT&T cellular connectivity and/or eSIM provisioning. There have been several complaints in several forums, including the MacRumors Forums, Reddit, and the Apple Support Community.
Affected users are unable to connect to the AT&T network for phone calls, text messages, or data and their iPhone is showing “SOS” as the connection.
I got my iPhone 18 on Friday. I have coverage through AT&T. I have been noticing that I have been getting SOS on my phone. WiFi works for the internet but I can’t make calls. Even if it doesn’t say SOS, trying to make a phone call is impossible now. I have tried everything. I went to AT&T and they know nothing about it. I’m going to the Apple Store today.
The US version of the iPhone 18 Pro Max is the only new iPhone that uses 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 other parts of the world. However, so far we don’t know if the Qualcomm modem is at the root of the problem.
If the problem is a sofrware issue, Apple may be able to include a fix for it in the next iOS 27 update. Apple is currently testing iOS 27.0.1, which is expected to be released in the very new future. We’ll find out then if it fixes the issue.