You're taking the right steps by enabling two-factor authentication and signing out and back into iCloud. However, if the iCloud Passwords & Keychain toggle remains greyed out on your iPhone 13 Pro Max running iOS 18.5, there are several possible reasons for this issue, along with corresponding solutions.
One of the most common causes is restrictions set through Screen Time. These restrictions can prevent changes to account settings, including iCloud Keychain. To check this, go to Settings > Screen Time > Content & Privacy Restrictions. If restrictions are enabled, tap on Account Changes and make sure it's set to Allow. Alternatively, try turning off Screen Time entirely by going to Settings > Screen Time > Turn Off Screen Time. Once disabled, check to see if the Keychain toggle becomes active.
Another potential issue could be related to your device’s security settings. iCloud Keychain requires that your iPhone has a passcode enabled and that your Apple ID security is fully up to date. To confirm this, go to Settings > Face ID & Passcode and ensure that a passcode is set. Also, check Settings > [Your Name] to ensure there are no security alerts or verification prompts pending for your Apple ID.
It's also important to make sure that iCloud Drive is turned on, as it supports several iCloud-related features. Navigate to Settings > [Your Name] > iCloud > iCloud Drive and ensure it’s enabled. If it's off, toggle it on and then recheck the Keychain setting.
If your iPhone was ever managed by a school, employer, or another organization, a Device Management Profile could be blocking access to Keychain. To check this, go to Settings > General > VPN & Device Management. If you see a profile listed, tap it to view its restrictions. If the device is now personal and the profile is no longer needed, removing it could resolve the issue.
Another helpful step is to reset your network settings. Sometimes, network-related configurations can interfere with iCloud services. To do this, go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. This won’t delete your personal data but will require you to re-enter Wi-Fi passwords.
Even though iOS 18.5 is current, it’s still worth checking for a software update just in case a minor patch has been released. Go to Settings > General > Software Update to ensure you're not running a beta version or an unstable release.
If you have a Mac signed into the same iCloud account, you can try enabling Keychain from your Mac instead. Open System Settings > Apple ID > iCloud > Passwords & Keychain and toggle it on. This sometimes triggers the setting to sync and become active across all devices.
If none of these steps resolve the issue and the toggle remains greyed out, the problem may be on Apple’s end or a result of a deeper configuration error. In that case, the best course of action is to contact Apple Support. Be sure to mention your device model, iOS version, and that you’ve already verified that two-factor authentication is enabled.
