camel-zipkin - Root Span Id is not reported if the route calls multiple route

from("direct:foo")
        .delay(1000)
        .to("direct:bar")
        .to("direct:moo")
        .to("direct:tar");

from("direct:bar")
        .delay(2000);

from("direct:moo")
        .delay(1000);

from("direct:tar")
        .delay(3000);

// add on completion after the route is done, but before the consumer writes the response
// this allows us to track the zipkin event before returning the response which is the right time
exchange.addOnCompletion(new SynchronizationAdapter() {
    @Override
    public void onAfterRoute(Route route, Exchange exchange) {
        String serviceName = getServiceName(exchange, route.getEndpoint(), true, false);
        Brave brave = getBrave(serviceName);
        if (brave != null) {
            serverResponse(brave, serviceName, exchange);
        }
    }

    @Override
    public String toString() {
        return "ZipkinTracerOnCompletion[" + routeId + "]";
    }
});