Comment 1 for bug 2066188

https://github.com/openstack-charmers/charm-rabbitmq-k8s/blob/54d248a5741b0c19381e7058fba43c981f1f0952/src/charm.py#L891-L895

https://github.com/openstack-charmers/charm-rabbitmq-k8s/blob/54d248a5741b0c19381e7058fba43c981f1f0952/src/charm.py#L856-L864

Indeed, those queues are undersized after the sunbeam resize operation. e.g.

- arguments:
    x-queue-type: quorum
  auto_delete: false
  consumer_capacity: 0
  consumer_utilisation: 0
  consumers: 0
  durable: true
  effective_policy_definition: {}
  exclusive: false
  garbage_collection:
    fullsweep_after: 65535
    max_heap_size: 0
    min_bin_vheap_size: 46422
    min_heap_size: 233
    minor_gcs: 5
  leader: <email address hidden>
  members:
    - <email address hidden> ########## <- only one member
  memory: 143172
  message_bytes: 0
  message_bytes_dlx: 0
  message_bytes_persistent: 0
  message_bytes_ram: 0
  message_bytes_ready: 0
  message_bytes_unacknowledged: 0
  messages: 0
  messages_details:
    rate: 0.0
  messages_dlx: 0
  messages_persistent: 0
  messages_ram: 0
  messages_ready: 0
  messages_ready_details:
    rate: 0.0
  messages_unacknowledged: 0
  messages_unacknowledged_details:
    rate: 0.0
  name: cinder-volume.cinder-ceph-0@cinder-ceph
  node: <email address hidden>
  online:
    - <email address hidden>
  open_files:
    <email address hidden>: 0
  operator_policy: None
  policy: None
  reductions: 33414
  reductions_details:
    rate: 401.0
  single_active_consumer_tag: None
  state: running
  type: quorum
  vhost: openstack

Not sure why grow_queues_onto_unit is not properly applied in this case.
https://github.com/openstack-charmers/charm-rabbitmq-k8s/blob/54d248a5741b0c19381e7058fba43c981f1f0952/src/charm.py#L402-L425