Fitted device so can remotely reboot WAN1 & WAN2.
Checked Loadbalancer by logging in and doing ping to www.bbc.co.uk
All three WAN ports failed ping test.
Had to reboot Loadbalancer to set it back to balancing between WAN1 and WAN2.
Load balancer started pinging out on WAN1 (as expected) failed to ping out on WAN2 (as expected because Be lines both in same subnet).
Loadbalancer would not ping out on WAN3 for a few minutes. Eventually WAN3 pings restarted without rebooting the router. It could be too much load on WAN3 made it fail.