iPhone 18 Pro Max loses signal on AT&T, and iOS 27.0.1 won't fix it
If you bought an iPhone 18 Pro Max in the US and use AT&T;, check your signal bars today. Some phones drop to an SOS-only status and never reconnect. Apple has now confirmed that a phone that has already lost service needs a hardware replacement. Reports of thousands of affected users have piled up since the phone launched on September 18. AT&T; says the fault can also block calls to 911.
The fix that isn't
AT&T; texted customers telling them to install iOS 27.0.1. That update does not appear to address the problem. Apple released it for a Face ID bug that could make iPhone 18 Pro models restart after a failed face scan. MacRumors notes the release notes never mention cellular connectivity, and many users say nothing changed after installing it.
Apple's own statement, reported by 9to5Mac, draws the line clearly. A carrier settings update (version 72.1, released October 2) should stop new cases. It will not bring back service on a phone that has already dropped off the network. Those owners need to contact Apple Support for a replacement.
The cause
Nobody has confirmed one. The US iPhone 18 Pro Max uses a Qualcomm Snapdragon X80 modem, the chip that handles cellular connections. The smaller iPhone 18 Pro and the Pro Max sold outside the US use Apple's own C2 modem. That makes the Qualcomm part a suspect, but neither Apple nor AT&T; has blamed it. Carrier provisioning or eSIM setup could also be involved.
The reports so far point to AT&T; specifically. No matching complaints have surfaced on Verizon or T-Mobile.
What it means in the US and UK
Buyers on other US carriers have no reason to panic. Buyers in the UK and elsewhere outside the US get the C2 modem version, and there are no reports of the same fault there.
AT&T; customers have a few options. Install the carrier update if the phone still works. If it shows SOS, book an Apple Support replacement and keep a backup of your data. Anyone who hasn't bought yet could wait, or look at rivals. The Galaxy S26 Ultra now costs more than the iPhone 18 Pro Max, so the price gap has shifted.
Apple still has to say whether the defect is in the hardware or whether a software fix is coming.
