From command line try this:
db networks set NICName ethernet role green ipaddr network.ip.to.assign netmask netmask.ip.to.assign gateway gateway.ip.to.assign onboot yes bootproto static
signal-event interface-update
Where:
NICName : is the device name of your network card (for example eth0 enp0s0)
network.ip.to.assign : it’s the IP to assign to your nethwork card
netmask.ip.to.assign : it’s the Netmask to assign to your network card
gateway.ip.to.assign : it’s the IP gateway of your lan
Then go to in cockpit or interface-manager, check and optionally reconfigure your lan interface configuration