AT&T Connectivity Problems Reported by Some iPhone 18 Pro Max Owners
A subset of iPhone 18 Pro Max users in the United States are reporting signal drops, failed calls, missing texts, and eSIM activation errors on AT&T. Affected devices may lose all cellular bars or fall into SOS mode, forcing owners to rely on Wi-Fi. Complaints have appeared on MacRumors forums, Reddit, and Apple support threads.
Reports center on U.S. iPhone 18 Pro Max units on AT&T. Users describe bars vanishing, calls failing, texts not arriving, mobile data unavailable, and eSIM setup errors. Some devices enter SOS mode, leaving Wi-Fi as the only connection. Complaints appear on MacRumors forums, Reddit, and Apple's support community.
The U.S. iPhone 18 Pro Max is the only new model this month using a Qualcomm modem. The smaller iPhone 18 Pro, iPhone Duo, and non-U.S. Pro Max models use Apple's C2 modem. Whether that hardware difference causes the AT&T problems remains unconfirmed.
If these reports persist, some U.S. iPhone 18 Pro Max owners on AT&T may face disrupted calls, messages, and mobile data, potentially increasing reliance on Wi-Fi and affecting work, emergencies, or daily coordination. The situation could also pressure Apple and AT&T to clarify compatibility and speed fixes, while other iPhone 18 users and international Pro Max owners may remain unaffected. Because the cause is unconfirmed, broader impact is uncertain.