Problems with the join adapter

We have 5 integration components, 1 of them uses the Join adapter. There is a single document that trigggers all these 5 integration components and gets back 5 replies (1 from each component).

When we fire 3 simultaneous requests, all the integration components that do not use the join adapter fires a reply back to each request.

For the join component, we only get 1 document back. The other 2 requests do not get any reply. We’ve tried document tracker and a java client program (using the client API) and both behaves in the same way.