Sending an event while another event is being processed does not work.

[brash-ram]

On our project, we wanted to update the library version from 2.0.RELEASE to 4.0.0, but because of this, we started having errors.
State machine configurations:

@Override
public void configure(StateMachineTransitionConfigurer<ReplacementState, ReplacementEvent> transitions) throws Exception {
    transitions
            .withExternal().source(ReplacementState.NEW).target(ReplacementState.PREPARED).event(ReplacementEvent.PREPARE)
          .and().withExternal().source(ReplacementState.PREPARED).target(ReplacementState.IN_WORK).event(ReplacementEvent.TO_WORK)
        .guard(toWorkGuard())
        .action(toWorkAction(), errorHandlingAction())
        .action(toReadyToInstallState())

The first action toWorkAction() is handled correctly. During the second action toReadyToInstallState(), a new event READY_TO_INSTALL is sent. But after a new event, the state machine closes without changing the state. In the following StateMachineListenerAdapter code after sending a new event Stage = STATEMACHINE_STOP and the code is not executed by condition.

@Override
public void stateContext(StateContext<ReplacementState, ReplacementEvent> stateContext) {
    if (stateContext.getStage().equals(StateContext.Stage.STATE_CHANGED) && stateContext.getEvent() != null) {
        var replacement = (AbstractReplacement) stateContext
                .getStateMachine()
                .getExtendedState()
                .getVariables()
                .getOrDefault(ReplacementStateMachineContextRepository.ENTITY_CONTEXT_KEY, null);
        ReplacementState state = stateContext.getTarget().getId();
        if (replacement != null) {
            if (ReplacementEvent.CLOSE.equals(stateContext.getEvent())) {
                baseReplacementService.updateStateSystem(replacement, stateContext.getEvent(), state);
            } else {
                baseReplacementService.updateState(replacement, stateContext.getEvent(), state);
            }
        }
    }
}

Let me remind you that no code has changed except for version 2.0.RELEASE to 4.0.0.