News in Short
- AT&T has acknowledged cellular issues affecting some iPhone 18 Pro Max users.
- Affected phones may lose access to calls, texts and mobile data.
- AT&T is urging customers to install iOS 27.0.1 immediately.
- Some affected users say the update has not resolved the connectivity problem.
- Devices can reportedly enter SOS mode when the issue occurs.
Some iPhone 18 Pro Max users on AT&T are facing cellular connectivity problems. AT&T has now acknowledged the issue through a text message sent to affected customers.
The carrier warned that some devices may be unable to complete calls, send texts or access mobile data. The warning also included emergency 911 calls.
AT&T is asking customers to install Apple’s iOS 27.0.1 update immediately. However, reports from affected users indicate that the update has not resolved the issue for everyone.
Calls, texts and data can stop working
The problem affects cellular connectivity on some iPhone 18 Pro Max units connected to AT&T’s network.
Affected users have reported losing access to phone calls, text messages and mobile data. In some cases, the device enters SOS mode after losing its connection to the network.
Reports about the problem have appeared across Apple’s Support Community, Reddit and MacRumors forums. MacRumors says thousands of users have reported experiencing the issue across these discussions.
The reports do not indicate that every iPhone 18 Pro Max on AT&T is affected.
AT&T asks users to install iOS 27.0.1
AT&T’s message specifically directs affected users to install iOS 27.0.1.
The carrier’s message says some phones may be unable to complete calls, texts or data, including calls to 911. It asks users to update through Settings > General > Software Update.
However, Apple’s release notes for iOS 27.0.1 did not list a fix for the AT&T cellular problem. The update was released with a fix for a Face ID issue affecting iPhone 18 Pro models.
Some users continue to report connectivity problems after installing the update. Forum reports also indicate that changing modem firmware with the update did not consistently resolve the problem.
Cause of the iPhone 18 Pro Max problem remains unclear
The exact cause has not been confirmed.
One hardware difference has drawn attention. The US version of the iPhone uses a Qualcomm cellular modem. Apple’s C2 modem powers the iPhone 18 Pro and iPhone Duo globally, while iPhone 18 Pro Max models outside the US also use the C2 modem.
However, there is currently no confirmation that the Qualcomm modem is responsible for the AT&T problem.
Apple has also not publicly identified the cause or confirmed that a hardware component is defective.
Another software update could be required
If the issue turns out to involve software or carrier connectivity, a future update could potentially address it.
A subsequent release such as iOS 27.0.2 has been suggested as one possibility if another software fix is needed. However, neither Apple nor AT&T has confirmed such an update as the solution.
If the underlying cause involves hardware, a software update would not resolve the problem. That possibility also remains unconfirmed.
What iPhone 18 Pro Max users should know
AT&T is currently directing affected customers to install iOS 27.0.1 and contact AT&T or Apple if problems continue.
The carrier already provides troubleshooting options for cellular issues on the iPhone 18 Pro Max, including checking signal settings and cellular configuration.
For now, there is no confirmed universal fix for the AT&T connectivity problem. Users who rely on their iPhone for calls or emergency communications should be aware that affected devices may temporarily lose cellular connectivity.
