os-ddclient plugin doesn't bind to specified interface

[aaravchen]

I'm on Opnsense 26.7.2_2, and fully up to date.

I have two gateways on my system, one is the regular WAN that's set as the default and is a CGNAT connection from the ISP. The second is a VPN interface that makes a Wireguard connection to a VPS server that has external ports exposed and is configured for port forwarding back to me. I'm configured for incoming traffic on my VPN interface to be NAT routed to a self-hosted server, and no traffic is setup to use that interface by default.

I have the os-ddclient plugin installed and have numerous domain names set to be updated from it so they route to my public server IP address. This is working for updating the addresses on my DNS provider, but the IP addresses it's retrieving are those from my WAN gateway interface rather than my VPN gateway interface. Even though I have all of the entries set to monitor my VPN gateway interface.
I'm running with the default "native" backend, but I've also tried setting it to the deprecated "ddclient" backend and it doesn't seem to matter.

Is there anything I can do to make the ddclient traffic route thru the VPN interface/gateway specifically? Or does the os-ddclient simply not support multi-wan setups (any multi-wan, no matter the priorities, would need the option to specify the exact interface/gateway to bind to)?