iphone 12 screen does not go dark when not in use

Did you set Auto Lock to Never?

Open Settings.

Navigate to "Display & Brightness".

Tap "Auto-Lock".

Choose the amount of time you want your screen to stay on.

Your options are:

30 Seconds, 1, 2, 3, 4, or 5 minutes or Never.

My iPhone 12 Pro will not turn off when I close it's wallet case cover like my iPhone X did. It was very handy when I closed the iPhone X's cover I would hear a click and the phone shut off and locked When you touched the screen after that you went to the Lock Screen and it scanned your face and opened. Now, to have the phone shut off I have to push the button on the right side of the iPhone and manually shut it off and lock it.

Is there a problem with my new iPhone 12 Pro or does the iPhone not do this anymore?