Apple has launched a new service program to fix iPhone 14 Plus phones with rear cameras that won't show a preview. The issue affects a small percentage of devices manufactured between April 10, 2023, and April 28, 2024. Affected phones will be serviced for free by Apple or an Authorized Service Provider, regardless of the phone's original purchase date. If you've already paid to have the camera repaired, you can reach out to Apple to request a refund.

Source: https://www.theverge.com/2024/11/1/24285851/some-iphone-14-plus-phones-have-a-camera-issue-but-apple-may-fix-it-for-free