Bluetooth Issue

[Frapa_]

Hi,
I have a problem with my phone (Android LG K500K) connecting to my car (Mazda CX-5). The phone connects or reconnect each time and I can see the current track Spotify is playing on the car's screen, but unless I go into the Spotify app on my phone it will not play. The app is pinned on my phone so is always running.

Can anyone advise what I need to do so the phone will connect and music play without the need to go into the app on my phone?

Thanks.
Paul