Comment 4 for bug 1915727

Some context for the variables:

    # List of virtualised compute hypervisors in this Ansible play batch.
    virt_computes_in_batch: >-
      {{ groups[nova_cell_compute_group] |
         intersect(ansible_play_batch) |
         list }}
    # List of iroinc compute hosts in this Ansible play batch.
    ironic_computes_in_batch: >-
      {{ (groups[nova_cell_compute_ironic_group] |
          intersect(ansible_play_batch) |
          list)
         if nova_cell_services['nova-compute-ironic'].enabled | bool else [] }}
    all_computes_in_batch: "{{ virt_computes_in_batch + ironic_computes_in_batch }}"

Perhaps the issue is those ironic computes, which typically run on controllers.