new bluetooth unit fitted to a columbus

Hello from Sweden 

I have a 2011 skoda yeti 4x4 160 with the columbus radio.

From the factory theres a bluetooth unit installed that lets me play music from my iphone 6 but wont let me change tracks with the buttons on the wheel/columbus, or display any kind of song info.

So i went on Ebay and bougt me a new unit with the version number "3C8035730E". according to google this bluetooth unit should fix alla my issues =)

I swapped the units and at a start it was looking great. the current song was displayed and i could change tracks with the buttons. but... theres a problem, no sound =(

its dead silent. if i press the bluetooth button again on my colombus it change the display to just "bluetooth audio" and the sound turns back on.

I have done a facotry reset on my colombus and reconnected my phone, but no cigar....

Any suggestions how i could fix this issue ?

do i need to find someone with a VCADs? 

if i push the setup button its only show the fm/am option, so i dont know wich firmware i have.