Unusual and dangerous bug.
And iOS 11 iOS 12 , have discovered a new very unusual and extremely nasty bug. Due to the flaws the operating system on the iPhone may not trigger the alarm, a scheduled event in the Calendar app and reminders. The issue is many users, so it definitely can be called a mass.
What kind of bug
If on the iPhone running iOS iOS 11 or 12 set two alerts at the same time, the alert won’t trigger. For example, if you set the alarm for 7 am and the event in the calendar at 8am with a reminder for an hour, no alarm clock, no notification about the planned business are not activated.
The same bug is manifested in other conditions. For example, if at the same time with the alarm clock set alarm function “sleep Mode”.
A bug in iOS makes such notification to cancel each other. As a result, the alarm clock simply does not work that can cause serious trouble.
The existence of the bug confirmed hundreds of iPhone users on the official Apple forum and the Reddit forum. Users have also sent a message about finding problems to the developers of Apple. It is expected that the bug will be fixed in the next updates of iOS 12.
What to do
In order to exclude the possibility of manifestation of a bug right now, it is sufficient to ensure that reminders are set for different times. Enough to put a difference between the alarm clock and reminders, or alarm functions “sleep Mode” in just one minute. In this case, notification will not be shut down.