State action is called twice in sub-submachine with fork/join

[errd]

Hi there!

Faced the issue when my state action is called twice when expected behaviour is to run once.
Here is my state machine:

The problem is that for some reason method setCurrentState of AbstractStateMachine is called twice for state STATE_11.
Once from line 991
return setCurrentState(f, message, transition, false, stateMachine, null, fps.getForks());
and another one on line 999
return setCurrentState(toState, message, transition, true, stateMachine, null, targets);
And this leads to execution of handlers and actions twice.

I created a demo project with described behaviour:
https://github.com/errd/spring-state-machine-example
Please find in the project a test placed in StateMachineTest class.

The problem persists only when I have fork/join in the submachine, with fork/join on the first level everything works as expected.

Am I missing something from configuration point of view?
Thanks in advance!