As much as I hate hearing it from any support person trying to help me with a tech problem, I also ask the infamous “Have you tried turning it on and off?” question when helping others with various issues. The question applies to iPhone and Android devices, just like any other computer. A restart can fix problems with the software, and it’s among the easiest things you can consider. Even if it’s just to have the satisfaction of telling the person trying to help you that you already did it.
But iPhones shutting down by themselves and then restarting isn’t the kind of feature you want. You wouldn’t want that from any computer unless you set automatic shutdown and restart timers. Some users have experienced this type of annoyance on iPhones recently, and it might be yet another serious bug that Apple has to fix.
Since this phenomenon appears to occur at night, you’d have no way of knowing it happened unless it impacted your alarm schedule or you checked for it. Thankfully, there is an easy way to check if your iPhone shut down and determine how long it stayed off.
As a reminder, iOS 17.0.3 should have fixed the iPhone 15 Pro/Max overheating problem. It did that to some extent, although some people are still complaining about the higher temperatures than expected.
It’s unclear at this time whether the iOS 17.0.3 release introduced the shutdown bug. Also, it might not be just iPhone 15 owners who experience the issue.
There’s a thread on Reddit where some users say older models have experienced what might be a shutdown issue. Some went through the same problem with older iPhones in the past. The Redditor who started the thread explained that the alarms of two iPhones in their household did not go off. When someone pointed out the shutdown bug, the Redditor said their device did not show a gap in the battery settings.
Check the battery settings
Alarms failing to ring in the morning can be a symptom of random shutdowns. The only way to tell whether your iPhone turned itself off on its own is to go to the Settings app, scroll to the Battery section, and look for the graph below.
Since iPhones are almost always turned on, the graph shows the evolution of battery charge during the day. Seeing several missing bars indicates the phone was off for several hours. Of course, you’d see similar gaps if you ran out of battery. But then again, most people recharge their iPhones at night, so the battery isn’t the issue.
There is one caveat. If your iPhone restarts immediately after shutting down, you won’t see any missing bars in the graph above.
Some people might say that iPhones turning themselves off and then back on again might not be a big problem. But the alarms failing, because the phone might have been off, is a massive issue. Not to mention that you’d be unreachable while the phone is off. Calls and texts would not go through from loved ones who might need immediate help.
It’s unclear why iPhones with this issue only shut down during the night.
Pay attention to Face ID not working in the morning
The alarm failing to ring because the handset is off is one symptom. Another is seeing the handset requesting a PIN code instead of unlocking via Face ID. This signals that someone used your iPhone at night or the phone restarted. When the iPhone restarts, it asks for your PIN code before Face ID becomes available again.
As I type this, I realize that I woke up to the iPhone requiring my PIN code a few times in the past year. It happened randomly, and I thought the iPhone just didn’t register my face properly.
I didn’t consider that the handset might have been shutting down and forgot about it. I usually install updates during the day, so the iPhone wouldn’t have restarted for that reason. That’s actually the only valid excuse for iPhones randomly restarting: Performing an automatic iOS update.
However, I haven’t experienced the issue on my iPhone 14 Pro recently. And I’m running the latest software update, iOS 17.0.3. Hopefully, Apple will fix the shutdown issues at some point in the near future with its iOS 17.0.4 update.