Connected to CX-5 audio system by Bluetooth but no sound!
 

My phone is connected to the CX-5 audio system via Bluetooth. It displays my music (or podcast etc.) but there is no any sound coming out. Does anyone have the same issue and what's the solution? The car is GT 2018.
When I connect by USB port then I have the sound.
I reset the system (turned the phone on/off, turned the car on/off, disconnected the Bluetooth and again connected) but still have the same issue.

Did you make sure you switched to your_phone_bluetooth under Music? What kind of phone is it?

Yes, I select the connection to my phone Bluetooth under music menu. And as I said the display shows my music playing on my phone but there is no any sound. When I select connecting to my phone via USB port then I have the sound. It's iphone 8 plus.

Yes, I select my phone Bluetooth under music. it shows the music is playing on the screen but no any sound.
It is iPhone 8 plus.