@doron92
I don’t know that this is much help but I just installed and used the most basic config entry (below) and the alarm turns off as expected, based on the timer setting in the config. I changed the timer value a few times and it follows that value. Try a basic config entry (such as this one) and see if it works. At least it’s a place for you to start troubleshooting.
{
module: 'MMM-AlarmClock',
position: 'top_right',
config: {
timer: 15 * 1000,
alarms: [
{time: "20:29", days: [0,1,2,3,4,5,6], title: "Soccer", message: "Get ready for soccer training!", sound: "alarm.mp3"},
],
}
},