How to monitor / log Multi-WAN functionning?
Is it possible to see somewhere a list of connections and via which interface it was done and why in Multi-WAN round-robin setup?
I suspect this feature works bad for me, but I feel I am completely blind here.
There isn't really a list like that to view. You can see the connections on Diagnostics > States, and they are listed by interface, but there is no "why" – the "why" is up to the policy routing rules on the internal interface (e.g. LAN) and that part isn't retained in a visible way.