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.
I’m not bothering with Apple Support, I’ve reported the issue through the Feedback application though as I’m on iOS 17.1 beta (much more likely to get a useful response to the issue then contacting support)