14 Pro Max: black screen after IOS 16.3.1 update

I’m using my daughter’s phone to post this and I’m so glad I didn’t update her iPhone or she’d have the same issue. I’m seeing a lot of posts online about the black screen of death after updating to IOS 16.3.1. None of the Apple Support people seem to know about this. 🤷🏻‍♀️ Hard reset doesn’t work. 😭 The IPhone is charged and the shop says battery is fine. It’s a 2-day wait for any of the Apple Genius Bars within a 50 mile radius. 😭😭