iPhone 18 Pro Max experiences cellular connectivity issues: thousands of users affected.

According to MacRumors, US carrier AT&T has confirmed that some US versions of the iPhone 18 Pro Max are experiencing cellular network malfunctions and stated that it is working with Apple to investigate the issue.

Since the device’s release on September 18, thousands of user reports have appeared on platforms such as the Apple Support Community and Reddit. Affected devices intermittently or completely disconnect from the AT&T network, unable to make calls, send or receive text messages, or use mobile data, and may even affect emergency calls, with the phone frequently automatically entering SOS emergency mode.

AT&T has sent text messages to users recommending that they upgrade to iOS 27.0.1 immediately. However, many affected users have reported that this version has not resolved the network issue.

The update log shows that iOS 27.0.1 only fixes Face ID-related vulnerabilities and does not list any network-related fixes. Internal emails from carriers also acknowledge that this update is solely for mitigating future risks.

For users who have already been affected, the only solution is to replace their phones and use new devices provided by Apple or AT&T.

It is understood that the US version of the iPhone 18 Pro Max is the only model in the new iPhone lineup equipped with a Qualcomm cellular baseband; other regional models, as well as the iPhone 18 Pro and iPhone Duo, all use Apple’s self-developed C2 baseband. However, there is currently no evidence to prove that the malfunction is directly caused by the baseband. Some users have had their warranty repairs and replacements refused by stores.

For consumers who purchased the device on September 18th, October 2nd is the deadline for Apple’s 14-day no-questions-asked return policy.