Thanks for the reply- I have tried turning the phone off and on, as well as toggling DND off and on, but am still getting seeing a notification that looks roughly like this:
"DO NOT DISTURB
Calls and notifications will be silenced until Do Not Disturb is turned off."
Clearing the notification makes it go away but only temporarily. Also, the little crescent moon is on the notification as well as on display up by the battery meter, as it was on iOS 11.
Thanks again for the help. I realize this is a minor issue, but on my phone, DND is always on and the notification banner runs right over a very adorable picture of my very adorable son on the lock screen.