Day 2 with my new 44MM Series 4 Aluminum. Certain apps, especially Facebook, do not give me the ding/haptic feedback with a notification. I double checked that notifications are on for all apps, silent mode is off and do not disturb is off. I have every app set to mirror iPhone alerts with sound on. It just seems to randomly choose when it wants to make a sound or not. Facebook notifications seem to be the worst. Even on my iPhone X the banner appears, but no sound or vibration. I restarted both and no change. I'm starting to think it's an individual App issue and not really related to the settings of the watch or phone itself.