Fail to connect Bluetooth to car audio system

I have tried to connect my iPhone 6 Plus to the Car Audio System that perfectly work with the previous android. The iPhone says connect but only the call talking work automatically, but the phone screen and media screen say that no phone is connected, then I need to do manually, search devices and connect an iPhone that says it is already connected.

What I would like to have is when I start the ignition all Bluetooth services are automatically connected, as it should be.

The car audio system is from VW 2010 2.1 version.

I already connected iPhone 5, 4S and iPad Air without problems. Could be from the iOS 11?