I just rec’d a new iPhone 11 Pro Max 2 days ago. After charging (came with zero charge) and backing up from ICloud, it began to just shut down. I’d put the phone down and pick it up to a black screen. Would have to press the button and apple logo would appear and password due to restart was required. Went through apple support and after HOURs of effort including updating iTunes, and doing the update through iTunes, the problem persisted. I was told it must be SW related and it was suggested I set up as a new phone. Reluctantly I tried this and after about 7-8 hours where I slowly MANUALLY reset up and configured my phone , linked to my watch etc the problem resurfaced. The same exact issue and sometimes it would even turn itself on when I picked up the phone (no button press). So off to the apple store I went where the analytics showed multiple “panic” logs. They confirmed it was HW then and provided me a replacement for my 2 day old phone. Apparently the guy had never seen this on this phone but this thread has me wondering. So for those of you with this same issue - it’s not your case. It’s not your SW. And it’s not from copying the image from your old phone. Check the analytics log and look for files that say panic... apparently just a couple is not an issue but if there are several.... red flag. Problem will not just resolve itself.