Can be reproduced with the latest charms by running the OpenStack upgrade tests from Stein to Train: [1]

$ tox -e openstack-upgrade kitchen-sink-bionic-stein

App                    Version  Status  Scale  Charm                  Store       Rev  OS      Notes
ceilometer             13.1.2   active      1  ceilometer             jujucharms  412  ubuntu
ceilometer-agent       13.1.2   active      3  ceilometer-agent       jujucharms  366  ubuntu
ceph-mon               14.2.22  active      3  ceph-mon               jujucharms  487  ubuntu
ceph-osd               14.2.22  active      3  ceph-osd               jujucharms  506  ubuntu
cinder                 15.6.0   active      1  cinder                 jujucharms  453  ubuntu
cinder-ceph            15.6.0   active      1  cinder-ceph            jujucharms  362  ubuntu
glance                 19.0.4   active      1  glance                 jujucharms  487  ubuntu
gnocchi                4.3.4    active      1  gnocchi                jujucharms  148  ubuntu
keystone               16.0.2   active      1  keystone               jujucharms  585  ubuntu
memcached                       active      1  memcached              jujucharms   34  ubuntu
mysql                  5.7.20   active      1  percona-cluster        jujucharms  302  ubuntu
neutron-api            15.3.4   active      1  neutron-api            jujucharms  490  ubuntu
neutron-gateway        15.3.4   active      1  neutron-gateway        jujucharms  469  ubuntu
neutron-openvswitch    15.3.4   active      3  neutron-openvswitch    jujucharms  457  ubuntu
nova-cloud-controller  20.6.1   active      1  nova-cloud-controller  jujucharms  560  ubuntu
nova-compute           20.6.1   active      3  nova-compute           jujucharms  587  ubuntu
placement              2.0.1    active      1  placement              jujucharms   67  ubuntu
rabbitmq-server        3.6.10   active      1  rabbitmq-server        jujucharms  450  ubuntu
swift-proxy            2.23.3   active      1  swift-proxy            jujucharms  239  ubuntu
swift-storage-z1       2.23.3   active      1  swift-storage          jujucharms  395  ubuntu
swift-storage-z2       2.23.3   active      1  swift-storage          jujucharms  395  ubuntu
swift-storage-z3       2.23.3   active      1  swift-storage          jujucharms  395  ubuntu

$ openstack compute service list
+----+------------------+------------------------------------------------------+----------+---------+-------+----------------------------+
| ID | Binary           | Host                                                 | Zone     | Status  | State | Updated At                 |
+----+------------------+------------------------------------------------------+----------+---------+-------+----------------------------+
|  1 | nova-consoleauth | juju-7c141d-zaza-21897d1d9780-15                     | internal | enabled | down  | 2021-12-17T10:27:19.000000 |
|  2 | nova-conductor   | juju-7c141d-zaza-21897d1d9780-15                     | internal | enabled | up    | 2021-12-17T14:14:17.000000 |
|  4 | nova-scheduler   | juju-7c141d-zaza-21897d1d9780-15                     | internal | enabled | up    | 2021-12-17T14:14:16.000000 |
|  6 | nova-compute     | juju-7c141d-zaza-21897d1d9780-16.project.serverstack | nova     | enabled | up    | 2021-12-17T14:14:10.000000 |
|  7 | nova-compute     | juju-7c141d-zaza-21897d1d9780-17.project.serverstack | nova     | enabled | up    | 2021-12-17T14:14:08.000000 |
|  8 | nova-compute     | juju-7c141d-zaza-21897d1d9780-18.project.serverstack | nova     | enabled | up    | 2021-12-17T14:14:16.000000 |
+----+------------------+------------------------------------------------------+----------+---------+-------+----------------------------+

[1]: https://github.com/AurelienLourot/charmed-openstack-tester/blob/bug/1951863/tests/openstack-upgrade/tests/tests.yaml#L75