How to upgrade an Aruba 8320 using Ansible

Here is what I’ve tried so far:

<b>tasks:
      - name: Running command
        become: yes
        become_method: enable
        aruba_command:
          provider:
            username: "{{ username_switch }}"
            password: "{{ password_switch }}"
          commands:
            - vsx update-software tftp://image_url....
            - auto-confirm
        register: upgrade

      - debug: msg="{{ upgrade.stdout_lines }}"</b>

The Playbook is successfully executed, however the vsx command fails and returning this output:

**"System is not ready. Please retry after few seconds.."**
What could be the cause of this odd behavior ? (the command is executed with success if done manually on the device)
Thank you in advance.