Had some issues again yesterday with messaging on Sync. This is the only way to get it back (until it decides to fail again):
1) Delete your phone from the car. Delete Sync from your phone. Wait a minute to make sure everything clears.
2) Turn the phone off and on again. You don't need to reboot the phone but make sure it is physically off and then on (not just lock and unlock). Turn the car off and then on again.
3) Pair your phone fresh w/MFT. Let it do its thing (phonebook loading, voicemail #, 911 assist, etc.).
4) On your phone, turn BT off. Turn it on again.
5) Hit "connect" on the MFT screen to reconnect BT.
6) Go into the settings screen for Sync. You should now see "Show Notifications".
7) Set Notifications to "On".
8) Back up a screen on the phone and turn BT off again. Turn it back on.
9) Hit "connect" on the MFT screen again to reconnect to BT.