AT&T and Apple are addressing widespread cellular connectivity problems affecting thousands of iPhone 18 Pro Max users. These issues prevent affected devices from connecting to the AT&T network for calls, texts, and data. The exact cause of these problems remains undisclosed. Apple has released a carrier settings update, version 72.1, which likely contains optimizations for the iPhone 18 Pro Max's cellular performance. Users will be prompted to install this update or can find it in Settings > General > About. Additionally, Apple is now requiring the installation of iOS 27.0.1 for new iPhone 18 Pro Max setups. Although this iOS update may not immediately fix existing issues for most users, AT&T suggests it is intended to mitigate future problems. AT&T has confirmed they are collaborating with Apple to resolve the situation. It is uncertain if further software or carrier updates will be necessary to fully rectify the cellular connectivity problems.