Why does not the notification light go off again?

I bought the Huawei mate 10 life yesterday. Today this lamp lights up since I started it up again and it just does not work out. (In the status bar is not displayed and I've also read all the WhatsApp messages) synonymous if I disable the notification light in the settings lights the next.

Did you restart the device?

In addition, something should be in the manual of the device…