Ansible shell passes a command without executing it

I am using ansible for the execution of a script (myScript.sh) over some nodes through the command:

- hosts: primaryNodes,!node13
  vars:
    mongodPath: /usr/local/mongodb
  become: yes
  become_user: user
  tasks:
  - name: starting mongod on all shards
    shell: "sh {{ mongodPath }}/myScript.sh"
    register: out
  - debug: var=out.stdout_lines

The execution of the script may need around 2-3 seconds or maybe less in order to give an output message on the shell (depending on the node). I am using the out.stdout_lines for debugging purposes, to be sure about the status of the execution.

Some nodes give as an output the following one which is correct;

ok: [node16] => {
    "out.stdout_lines": [
        "about to fork child process, waiting until server is ready for connections.", 
        "forked process: 2837", 
        "child process started successfully, parent exiting"
    ]
}

But some other nodes, seem to have passed the command, without executing it;

ok: [node2] => {
    "out.stdout_lines": []
}

I have managed to solve this by using the following playbook (added sleep) – all the nodes now give the desired output message (child process started successfully);

- hosts: primaryNodes,!node13
  vars:
    mongodPath: /usr/local/mongodb
  become: yes
  become_user: user
  tasks:
  - name: starting mongod on all shards
    shell: "sh {{ mongodPath }}/myScript.sh && sleep 5s"
    register: out
  - debug: var=out.stdout_lines

I know that this is a rough solution for my case, but is there a way to wait for a responding message from the node?