No notification when connected to aux

[BSG5]

HI
I have a Samsung Galaxy S5
When I have my aux plugged into the car I don't receive any notification sounds so I dont know when I receive a message
Can I fix this problem

 

[SpookDroid]

I'm not sure why, I have the same issue for a while. It seems notifications are still played through the phone and any notification via BT or AUX, is very low (it is there, it's just barely audible unless you've cranked up the volume). It also seems to happen with stock apps, not with 3rd party ones with custom notification sounds.