Hi.... just upgraded to the Galaxy S9.
I've turned off the "show only the 3 most recent notifications icons on the status bar" feature using: Settings>Display>Status Bar
However, I'm still receiving app notifications from Messenger, email and Outlook on the Status Bar, (so far...) which I really don't like or want. I've checked within these apps notifications settings to see if there's anything in there to stop them and there isn't. I just want it to be the same as my Galaxy S7 edge!
According to other users and YouTube videos, the "show only the 3 most recent notifications icons on the status bar" setting as previously mentioned, SHOULD turn these notifications off!
under messenger there is an option to turn off notifications.
Next for " GMAIL
1. Go to your " Gmail App
2. Go to " Settings
3. Go to " General Settings
4. Go to " Manage Notifications
' This is where you want to be for your " Gmail App
Hope this helps.