ddclient doesn't support multi-wan ip update

[franciz]

I have been trying to get a domain ddns working in a dual wan enviroment using failover.
I followed option B of this message:
https://forum.opnsense.org/index.php?topic=34139.msg165202#msg165202

But it doesn't work for me, I want to update the same domain on both interfaces.
But when WAN1 goes down, I always get the error "no global IP address detected, check config if warning persists". It would seem that it doesn't recognize interface WAN2 as being the active one now.

What can I check/test/config?

PS: Forgot to say, WAN2 is pppoe. Can it be the problem since the IP is not in the interface but in the conection?
(stupid comment since it is not reading interface IP but curling it out)

PS2: If I DISABLE WAN1 gateway, the curl command works and ddclient works too.
If I DISCONNECT the cable on WAN1 for testing purposes, the GW1 goes down but the curl command does not work (neither does ddclient obviously)
Ideas? missing firewall rule?