All error codes

router_port_vpn

HTTP 409 This public port is used by the router VPN

What happened

The public port of the forward covers the port of the router's WireGuard or OpenVPN tunnel, including a tunnel that is currently switched off. The forward would silently take the port away from the VPN devices.

What to do

Pick another public port, or use a different port range, then repeat with the same idempotency key.

Retrying

Change the state this refers to, then repeat the same request with the same idempotency key.

How it arrives

{
    "type": "https://docs.fiberax.com/errors/router_port_vpn",
    "title": "This public port is used by the router VPN",
    "status": 409,
    "code": "router_port_vpn",
    "request_id": "a277dcd1ca652c65"
}

Branch your code on code, never on the wording of title.