Link Status / Speed Wan Port Asus Router

[tokyo_networking]

I have an Asus ZenWifi AX (XT8) with the 2.5G WAN port connected to a 10G ONU port. The ONU seems to indicate a link has been established, but the Asus system log has a message which says WAN down.

I can see the following messages in the syslog which I assume relate to the LAN ports

May 5 14:05:23 kernel: eth1: sysport_tm port shaper set to 999000 kbps, 35000 mbs (phy speed 1000000 kbps)
May 5 14:05:23 kernel: eth1 (Ext switch port: 0) (Logical Port: 8) (phyId: 0) Link Up at 1000 mbps full duplex
May 5 14:05:23 kernel: eth3 (Ext switch port: 2) (Logical Port: 10) (phyId: 2) Link DOWN.

eth4 to eth6 seems to refer to Wireless interfaces.

eth0 seems to be up at 2.5G

May 5 14:05:38 kernel: eth0: sysport_tm port shaper set to 2497500 kbps, 150000 mbs (phy speed 2500000 kbps)
May 5 14:05:38 kernel: eth0 (Int switch port: 1) (Logical Port: 1) (phyId: 1f) Link Up at 2500 mbps full duplex

but previous to this it says

May 5 14:05:28 WAN Connection: WAN(0) link down.

I am trying to establish a Japan specific v6plus connection, but the router is unable to connect to the MAP server.

May 5 14:06:08 [MAP-E]: v6plus starts.
May 5 14:06:58 [MAP-E]: Map server did not reply(0). Reconfirm after 7 min.

Does any one knows what the WAN link down means? I assume it is not referring to the physical link being down.