I chatted with Apple support and they seemed to think the gap in the battery graph was normal if the screen was off?
I have suspicions that Focus modes also have some impact as to how the graph is displayed but haven’t confirmed it yet. The support rep seemed to think the passcode prompt was a coincidence as it’s something iPhone will prompt for after 6.5 days of not using a passcode.
I had an iPhone 15 plus that was showing a last status of “10 hours ago” in Find My. Once I called it, it immediately checked in and the battery graph on that phone showed a gap right up until the moment I called the phone.
The missing data on the graph is likely just a graphical glitch as a result of the crash.
iPhone crashes. Reboots. Data either not getting recorded or not being shown to the user due to the bug.
I doubt the phone stays off for any extended period of time, that’s a hard sell for me given it always shows the password screen. No one has yet to hold power to boot their device.
It’s unlikely this is always at night. Crashes that happen in the day are resolved almost instantly by the user and likely wouldn’t garner much online attention, so it also makes sense that the reports only skew towards those when people aren’t actively engaging with their devices.
The crash could be a myriad of things, who knows but Apple.