iPhone 18 Pro Max clicking sound on UI interactions (iOS 27.0)

Device: iPhone 18 Pro Max

iOS: 27.0

Age: 3 days old (brand new)

I'm hearing an intermittent clicking/crackling sound during UI interactions. It happens even with media volume at 0 and Silent Mode on, so it's not media audio.

Confirmed triggers:

- Rapidly toggling Airplane Mode in Control Center

- Scrolling in apps

- Tapping the comment field in Facebook/Messenger

- Tapping any text field to bring up the keyboard (happens constantly, very easy to reproduce)

Does NOT happen with:

- WiFi toggle

- Playing audio through the speaker (speaker itself sounds fine)

Troubleshooting already done (issue persists through all of it):

- Multiple restarts

- Reset All Settings

- Full clean restore via Recovery Mode (not from backup)

- Turned off System Haptics and Lock Sound in Settings

- Enabled Silent Mode (physical switch) - sound still occurs

- Deleted Facebook/Messenger - sound still occurs

Key finding: The sound occurred even on the initial setup screen, before Apple ID sign-in and before installing any apps - so this isn't caused by a third-party app or restored data.

Is this a known iOS 27 haptic/software issue, or should I treat this as a hardware defect and request a replacement? Has anyone else experienced this on iPhone 18 Pro Max?