Ethernet not working

Hi Guys,
Recently i bought 4 rock pi’s out of 4 one of the rock pi ethernet is not working , led is blinking but no eth0 in interface list or dmesg , tried changing cables/ports , nothing . im using same armbian ubuntu bionic on all 4 , 3 are working perfect, maybe hardware issue?

Have you tried using the exact same SD that is used in a RockPi 4 with working ethernet?

Yes, ethernet is working on other rock Pi with same emmc