iPhone 15 Pro Max stuck on preparing update

17.4.1 should be installed using a computer; there were 2 versions of 17.4.1, and the 2nd, that fixed an unpublicized problem, can only be installed using a computer.

Troubleshooting steps:

• Restart your Mac just before starting the update
• Disable any antivirus, 3rd party firewall, “cleaning” app
• Delete any VPN profiles or apps on your computer
• Start the update
• If it still doesn’t update restart your Mac in Safe Mode→Start up your Mac in safe mode - Apple Support

Please update via a pc or mac instead

Update your iPhone using a Mac with macOS Catalina or higher

On a Mac with macOS Catalina or higher, you will use the finder in order to upgrade your iPhone. Make sure to Back up your device before starting the upgrade process.

On a Mac with macOS Catalina or later, you will follow the following steps:

1. Open a finder window
2. Connect your device to your Mac via a lighting to usb A or a lightning to usb c cable On the iPhone 15 series, use an usb c to usb c cable.
3. Select your device in the left sidebar of the finder window
4. click general, then click check for update
5. Click download and update.
6. If asked, enter your iPhone passcode

Update your iPhone via a Mac running macOS Mojave or earlier, or on a Windows PC

On macOS Mojave or earlier, or on a windows machine, we won't use the Finder to upgrade your iOS

Instead, we will use iTunes. Make sure to Back up your device before doing any update or upgrade to your phone.

1. Open iTunes
2. connect your device to the computer with an lightning to usb a or a lightning to usb c cable. On the iPhone 15 series, use an usb c to usb c cable.
3. Click device button in the iTunes toolbar
4. In the summary tab, click check for update
5. Click download and update, follow The on screen instructions
6. If asked, enter your iPhone passcode.

Updating/upgrading your iPhone - Apple Community