Which are dismal, to say the least. I use FB Messenger because so many other people I know do. And I have chat heads ON, so my notifications pop up. However, on my Galaxy Note 8 the chat heads override Do Not Disturb mode... I'll be falling asleep at night, the Note 8's screen on a very dim clock... and suddenly I'm blinded by some bright chat head! How do I set chat heads to not pop up if the phone is in Do Not Disturb mode? I went to the phone's Settings --> Do Not Disturb and there's a section for "App rules" - when I select it, it's a blank screen with "No rules" displayed and NO OPTION to set any rules! Messenger's settings are useless. It's all or nothing: either I turn chat heads on or off... but there's no way to set time limits. Any ideas?