Async Service Operation App Class Handler is not firing

Hello,

I created an async request/response service operation by using the Create Web service utility, and assigned an application class handler to the service op.

This web service call is from a third party, and uses the Anonymous node. I am using SOAP UI as a third party tool.

When I fire off the request from SOAP UI, I can see the transaction and message in the operation monitor. The status says 'DONE'

But the application class handler is not firing.

If, in the operation monitor, I click on the handler tester link for that transaction - it brings me to the handler tester page with the values populated from that transaction. I click 'Invoke operation', and now the app class handler is fired, and there are no errors.