iPhone 18 Pro Max stuck in SOS mode? Try AT&T’s urgent fix ASAP

Since the iPhone 18 series launched last week, owners of the top-tier iPhone 18 Pro Max on AT&T have reported losing the ability to make calls, send texts, use data and reach 911 emergency services. Posts on Reddit and other support forums describe phones randomly dropping into SOS mode, a state where the device shows no cellular connection, while Wi-Fi continues to work normally. AT&T has not explained the cause.

AT&T sent customers a text message stating that an important Apple software update is available and that some phones may be unable to complete calls, texts, data or 911 calls. The carrier told recipients to update to iOS 27.0.1 immediately through Settings, then General, then Software Update.

The problems appear limited to the iPhone 18 Pro Max; no other iPhone 18 model is affected. According to ZDNET, the Pro Max may use a Qualcomm modem while the rest of the iPhone 18 lineup uses Apple's C2 modem, though the cause remains unconfirmed. Apple's release notes for iOS 27.0.1 mention fixes for a freezing problem, a Face ID glitch and several smaller issues, but do not reference AT&T, the modem or network connectivity.

Applying iOS 27.0.1 works for some users, according to Reddit posts, but does not resolve the issue for everyone. An AT&T representative said Apple released the update to address a problem that may affect calls, data, texts and 911 calls on a small number of iPhone 18 Pro Max phones, and that customers should update now. The carrier said it is working with Apple and that customers still having trouble can visit an Apple or AT&T store for additional support.

Why it matters: iPhone 18 Pro Max owners on AT&T can lose ordinary calling, texting and data service, and emergency 911 access, until the issue is resolved. The recommended first step is installing iOS 27.0.1, though some users report it does not fix the problem, leaving store visits and carrier support as the remaining options AT&T names.