Nitecore EC21 keeps blinking red

Salut!

My EC21 blinks every now and then with the red 3mm LED.
I have looked into the manual, but nowhere says it anything about this.
Like a couple of minutes ago, it just flashed in ~1.5Hz for around 15 times and then stopped. It was the first time that I saw that light blinking in quite a while, maybe even weeks.

It doesn’t bother me too much, but I would just like to know what that is and how to get rid of it?

Thanks!