Bluesound Node N130

Hi I have replaced my Sonos Connect gen1, to Node N130. The Node can not work properly with coax cable it creates micro pauses and I can see that the display on my Simaudio flashes for one second, what is wrong? No problem on the Connect. I have tried two different cables same result. With optical cable no problem. The Node is connected with Ethernet cable (500Mbps).

Any clues