A subset of iPhone 18 Pro Max users in the U.S. are reporting problems with AT&T cellular connectivity and eSIM provisioning, according to complaints posted across the MacRumors Forums, Reddit, and the Apple Support Community.
Affected users say they are unable to connect to the AT&T network for phone calls, text messages, or mobile data, rendering standard cellular services unavailable for those devices.
Reports have appeared across multiple online communities, where impacted owners describe failures in both traditional cellular registration and eSIM activation or provisioning.
iPhone 18 Pro Max hardware differences and possible link
Notably, the U.S. version of the iPhone 18 Pro Max is the only new iPhone released this month equipped with a Qualcomm cellular modem. The smaller iPhone 18 Pro and the iPhone Duo use Apple’s C2 modem worldwide, and the iPhone 18 Pro Max uses the C2 modem in all other countries. It is unclear whether the modem difference is a contributing factor to the AT&T issues.
Apple is currently testing iOS 27.0.1, which is expected to be released next week, and hopefully it includes a carrier update that resolves these AT&T issues.
