Happened whilst charging, was on 39% when I connected it to the charger, fell asleep for a couple of hours woke up to the Apple logo and it restarting, it was fully charged upon booting back up.
Wonder what’s causing this? I’m also on iOS 17.1 Beta 3 so isn’t just an issue relating to just iOS 17.0, 17.0.1, 17.0.2 and 17.0.3 etc as some has suggested.
Do you use NightStand? That is the only thing different for me, other than 17.0.3. I know this happened at least once because FaceID said “iPhone requires a password when it restarts” and I checked for a software update, which was unchanged.