Thank you for the quick reply. I did two factory resets, and it seems to work well now.
About the light, I’m sorry if I didn’t explain it clearly. The light didn’t work when I clicked on the light button. The alarm didn’t work either. For now, all good. 
EDIT: The problem is back. After several tests, the light doesn’t work when I click on it, and the alarm does not work. I’ve contacted support.