The Control Center will not save the ethernet configuration if a static route added on Ethernet tab is invalid.
"New ethernet settings found to be invalid and cannot be saved for specified host. Old settings are retained."
The Control Center will not save the ethernet configuration with an invalid configuration or an address that is already in use.
Ensure the IP address being added is not already in use and the network information is valid and the network card is on the correct network (VLAN).
Investigate the configured static routes to determine and remove which item is not valid.
Information on editing the Ethernet configuration can be found in Configuring IPv4 Ethernet settings and routes.
OR for IPv6, Configuring IPv6 Ethernet settings and routes.