I set an alarm for 7:00, during week days, and I noticed that most of the time it doesn't go off. If I set another alarm, within a couple of minutes, it works fine.
It seems that I posted discussion too quickly, I didn't add my details.
The device is a Samsung Note 4, Android 6.0.1. To reproduce the issue, simply set an alarm for 7 AM, Mon-Fri, you should notice that often it doesn't go off.
Сервис поддержки клиентов работает на платформе UserEcho