I upgraded my iPhone 6S to iOS 11 this year, and now the alarm clock occasionally doesn't ring even I make sure silent mode is turned off, the ringer volume is up and I have enough battery.
This is, of course, only an educated guess. I wasn't awake because there was no alarm, so maybe I didn't hear it, right? Nope, I tested the scenario when the alarm rings indefinitely, and there should be a notification on the screen when I wake up (on some forums it says it rings for about 15 min and then it pops this notification).
Is there any way to check the logs for the alarm app? I checked out Xcode's
Devices and Simulators, but I can only see crashes.