odd phone/speaker issue

I have my moto g6 setup to autoconnect with the car and it does this fine. if i receive an incoming call it plays through the car speakers fine. However if i make a call it seems to default to the phone speaker rather than the being able to talk out loud as usual handsfree. if i toggle the mic icon on the infotainment screen it works as it should handsfree. Any ideas why it does this?