"Unable to verify this iPhone has a genuine Apple display"

You will see that message if you had the screen replaced, and the replacement screen was not a genuine Apple screen. Here’s more information→About genuine iPhone displays - Apple Support

The answer is in the link I posted, where it says:

You will see a notification on your Lock screen for the first 4 days that you use your device and in the Settings app for 15 days. After that period, you can find the notification by going to Settings > General > About.

You cannot remove it from Settings/General/About. You will also notice that some functions may not work, like True Tone and automatic brightness.

Right in this thread. Here’s a link to my post: https://discussions.apple.com/thread/253182436?answerId=255954505022#255954505022