Just that - I was asleep and dreaming when my watch buzzed. Checked the watch and had gotten the end of sleep notification. Couldn't really go back to sleep after that so I ended up reading for a bit. The app now says my wakeup time was 40 minutes later and that my sleep score was lowered because I was awake for an additional 40 minutes when I should have been sleeping. Sigh.
If you had sleep mode on, that message should not have woken you, as DND is activated in sleep mode. Check the parameters of DND in sleep mode to make sure that notifications from Samsung Health are off. Make sure you have enabled notification categories for each app and check the notification categories for the health app and make sure sleep is toggled off.
