Funny you should ask this question. I have a Verizon Samsung Galaxy Note 5 that I use with a Samsung Level U around the neck Bluetooth headset. Not sure which is the offender. Without changing ANY settings on either, I'd say notifications (sound or vibrate) work maybe 70% of the time. If there is multiple back and forth, it may sound/vubrate for the 1st few and then NOTHING for the rest. With the Level U, it's supposed to SPEAK the messages to you, that probably happens only 50% of the time on any given day with NO setting change