AT&T has urged iPhone 18 Pro Max customers in the United States to update immediately. It warned this week that some devices may fail calls, texts and data, including 911 calls.
The carrier advised customers to install iOS 27.0.1 through Settings > General > Software Update.
Some users on Reddit and the Apple Support Community say their connectivity problems continue after installing the update. Complaints about the model’s cellular service have circulated for more than a week.
In a statement to MacRumors on Friday, AT&T said it was “working with Apple” to resolve the problems. It directed customers with continuing difficulties to an Apple or AT&T store for further support.
Some customers say replacement phones restored their connectivity.
Read: iPhone 11 and Newer Support iOS 27 Compatibility
Apple’s release notes list fixes for a Face ID bug, camera colour artefacts and an unresponsive touchscreen. They do not mention a cellular fix. Apple has not publicly explained what causes the failures.
