API Proxy with a shared flow disfunction when tracing enabled

[amitmarx]

Hey,
I have a shared flow responsible for sending request & response information to a logging server.
The shared flow contains a JS policy to construct the payload, and a ServiceCallout policy to actually send it in an async manner.
I've applied the shared flow using the Flow Hooks (using the Post-proxy hook).

It all works great until I start a trace session on the API Proxy.
When I use the trace, the original request to the API Proxy is hanged and basically the API Proxy is out of service.
Even when I stop the trace session, it still takes the API Proxy about 20 minutes to start work again.

Attached a PS from the trace window, notice that the transaction never completes.
In addition, even the fact the ServiceCallout policy missing in the tracing diagram, I see this request on my logging server.

Has anyone tackled this issue before, is this a bug in Apigee?
(I doubt it is an issue with the shared flow, as it works fine without the trace, but I'd be happy to be found wrong)