WAN Load Balancing when interface stays up

[pepe]

@level410

load-balancing {
    wan {
        flush-connections
        interface-health eth0 {
            nexthop 1.1.1.1
        }
        interface-health wwan0 {
            nexthop 8.8.8.8
        }
        rule 1 {
            failover
            inbound-interface eth1
            interface eth0 {
                weight 100
            }
            interface wwan0 {
                weight 1
            }
        }
    }
}

You configured all interfaces as failover. One should be set as primary interface. Try change to:

        rule 1 {
            inbound-interface eth1
            interface eth0 {
            }
        }
        rule 2 {
            failover
            inbound-interface eth1
            interface wwan0 {
            }
        }

Documentation: WAN load balancing — VyOS 1.3.x (equuleus) documentation