Orquesta's sub-workflow is the type of 'with', it can not work normally

SUMMARY

The process cannot continue.
The sub-workflow is the type of 'with', and it have inquiry task. when i response all inquiry(The time difference is very small), the workflow’s status is still paused, the workflow not continue to run.

STACKSTORM VERSION

Paste the output of st2 --version:
st2 3.1.0, on Python 2.7.6

OS, environment, install method

Post what OS you are running this on, along with any other relevant information/

docker, from https://github.com/StackStorm/st2-docker

Steps to reproduce the problem

Show how to reproduce the problem, using a minimal test-case. Make sure to include any content
(pack content - workflows, actions, etc.) which are needed to reproduce the problem.

workflow

version: 1.0

input:
  - inputA:

vars:
  - listA: [{"a": 1},{"a": 2},{"a": 3},{"a": 4}]
  - summary:

tasks:
  subWorkflow:
    with:
      items: <% ctx().listA %>
    action: default.sub-test
    input:
      inputA: <% item() %>
    next:
      - do: echoTask
        publish:
          - summary: <% result().output %>

  echoTask:
    action: core.echo
    input:
      message: "test"

sub workflow

version: 1.0

input:
  - inputA

tasks:
  wait:
    action: core.local
    input:
      cmd: sleep 2
    next:
      - do: ask

  ask:
    action: core.ask

output:
  - inputA: <% ctx().inputA %>

1. run the workflow
2. when it created 4 inquiry , use postman response inquiries at the same time.(The time difference is very small)

Expected Results

What did you expect to happen when running the steps above?

subWorkflow and echoTask should be succeeded.

Actual Results

What happened? What output did you get?

the workflow status is still paused. the echoTask is not running

Run the supplied workflow with four sub-workflow items, then respond to all inquiry tasks nearly simultaneously through the described Postman flow. Trace the subWorkflow status and inquiry-response handling until the parent workflow can advance to echoTask; done means both subWorkflow and echoTask reach succeeded instead of remaining paused.