sonos port / marantz sr5015 no sound

Hey guys,

I’ve recently bought a marantz amp for my home theatre surround sound (passive, non Sonos) and a port to get Sonos in the room. I’ve plugged the Sonos rcas from out on the port into cd in on the marantz and have no sound. 
 

sonos port is connected fine and shows it’s playing. It’s playing in other zones fine. Volume output I’ve tried fixed, variable and pass through…. 
 

also have sound through tv input on the marantz which is fine..

any other tips 🙏🙏?

cheers

jon