Bluetooth earpiece not working on Google maps

Moto G4, Motorola H375 Bluetooth earpiece, latest version of Google Maps.

Phone Settings = Bluetooth ON
Google Maps Settings = Play Voice during phone calls ON, Play voice over Bluetooth ON.

Have tried different Bluetooth earpieces and un-pairing and re-pairing the H375 Bluetooth earpiece.

No mater what I have done the sound still comes from the phone speakers. Both Blurtooth earpieces work fine on telephone calls.

I may be wrong but I believe the headset needs to support media audio streaming, not just phone audio.