tftp server does not start on all IP addresses

I have several Virtual Interfaces vlan tagged all with fixed IP addresses.

192.168.1.102
192.168.1.103
192.168.1.104

and so on.

I need to run a TFTP server on all of them. However when I start it via command line or using the well known TFTPServer.app it only starts on the top IP address. In this case 192.168.1.102.

It does not respond on the other IP addresses.

If I move IP address 192.168.1.103 to the top in network sys pref then that address will work and not the others.

I have the same problem if I just create a new service with a fixed IP and no vlan tag.

Can anyone help? do I need to edit the tftp.plist file? If so I would need the exact thing to write in as I have tried to work this out and failed…