I've had the Android Pie update for a few days now and for the most part it's really nice.
I have noticed that when you pull down the notification shade once, you are able to see the notification in the notification shade. However, when you pull it down another time, you are no longer able to the the notification, but just the settings toggles.
It would be nice if you could also see the notification when you pull down the notification tray twice. This would be good for one-handed use, which is what Samsung's aim was for OneUI