1st reboot - same issue, alarm vanished
2nd reboot - same issue, alarm vanished
3rd reboot - alarm remain
4th reboot - alarm remain
5th reboot - alarm vanished!!

btw, even the reboot sequences are really weird with the USB plugged in (sync & connect mode):

1. reboot with USB plugged in by pressing the power button - the phone auto reboot back on after a few LED blinking (THIS seem like an abnormal behaviour as it only happen randomly, here it happen on the 1st reboot)

2. reboot with USB plugged in by pressing the power button - the phone not auto reboot back, just stay off with a Charging Icon on the screen until another power button press to boot up. (THIS seem a normal behaviour as it happen on 3 reboot)

Will keep more trial, this alarm vanishing bugs really annoy me lots...