Since the iPhone 18 series launched, some AT&T customers with the Pro Max model have seen their phones randomly enter SOS mode, cutting off calls, texts, data, and even 911 access. Wi-Fi remains unaffected, and the problem does not appear on other iPhone 18 models, suggesting a hardware-specific issue with the Pro Max's Qualcomm modem rather than a broader network fault.
AT&T has sent text alerts telling affected customers to install iOS 27.0.1, and Apple's update does resolve the issue for some users. However, forum posts indicate that many still experience the problem after updating. AT&T says it is working with Apple on a fix and notes that the affected number is small. Customers who continue to have trouble are directed to Apple or AT&T stores for support.