VM Console Access Error

Xenial-Mitaka to Xenial-Newton Upgrade.

Nova-Cloud Controller has 3 units with HA-Clustered, MemCache also enabled with relation inside the bundle.

  nova-cloud-controller:
    charm: cs:xenial/nova-cloud-controller
    num_units: 3
    options:
      openstack-origin: *os-origin
      network-manager: Neutron
      os-admin-network: *os-admin-network
      os-internal-network: *os-internal-network
      os-public-network: *os-public-network
      ha-bindiface: *ha-iface
      vip: *vip-nova
      use-internal-endpoints: true
      console-access-protocol: novnc
      single-nova-consoleauth: false
      cpu-allocation-ratio: *cpu-allocation-ratio
      ram-allocation-ratio: *ram-allocation-ratio
      worker-multiplier: *worker-multiplier
    to:
    - lxd:0
    - lxd:1
    - lxd:2
  memcached:
    charm: cs:xenial/memcached
    num_units: 3
    options:
      allow-ufw-ip6-softfail: true
    to:
    - lxd:3
    - lxd:4
    - lxd:5

- - nova-cloud-controller:memcache
  - memcached:cache

Pre-Upgrade there is no issue (Xenial-Mitaka), in all console access attempts we can reach VM Console with no issue.

Post-Upgrade (Xenial-Newton), 1 out of 3 attempts to VM console succeeds only.