This has happened too with my iPhone 15 Pro Max past two nights. Ive had the phone a month, no updates since 17.1.1 came out few weeks ago. Its Nov 25, 2023 It's been on 17.1.1 IOS past weeks, no issue till morning before last. Both nights the cat woke me up early, when I tapped the screen for some light it remained black. I was in do not disturb time. One thing that was different was previously to two days ago under 17.1.1 I had put the phone face down with wireless charging, the past two night I sat in normal reclining position face up in the cradle. Reason being the display light being on bothered me on earlier versions of IOS. Both times these las two mornings phone acted like expect but totally black screen. This morning I plugged the phone into my U2723 dell monitor unplugging the monitor from my MacBook USB port as it was a handy powered usb port. To my surprise the iPhone screen popped up on the dell monitor. However it would not show the unmark to log in and it stated the Face ID needed my pass code. literally on a black screen I tried to find where my passcode numbers were on the screen, on my dell monitor I would see I had mistyped till it timed me out. Note,About 15-30 minutes earlier I had tried to reboot the phone, prior to this attempt my Dell monitor. Now when on my Dell monitor I saw the phone had locked out password attempts for a minute, I walked away, when I came back couple minutes later, the screen was back normal.
The previous night I got up with it the iPhone screen blank, I had tried rebooting but it took like 15-30 minutes for the phone to return to normal operation .
So in my case seems it has something to do with phone not being face down while in do not disturb mode. Rebooting takes 15-30 minutes to clear the issue with absolutely no sign its doing anything. Clues to what the IOS displays on a USB monitor gives a clue to where the software bug is at.