Comment 1 for bug 1849588

Having the same issue while bootstraping juju controller for k8s model on top of Openstack cloud.
Juju version 2.7.2

Same flavor openstack server create to the same zone, I get success rate 5/5 (server created in z2):
openstack server create --image ubuntu-bionic-cloudimg --flavor m1.large --availability-zone z2 --network ext_net z222

However trying to bootstrap to this zone gets me controller in zone3 (constant).

juju bootstrap --bootstrap-constraints zones=z2 --model-default /home/ubuntu/alex/deployment/generated/juju_openstack_controller/model_defaults.yaml --metadata-source /home/ubuntu/alex/deployment/generated/juju_openstack_controller/images openstack_cloud foundation-openstack

After disabling all hypervisors in zone3, the same bootstrap command gets me controller in zone2 no problem.
After enabling back the hypervisor in zone3, the controller goes there again, so looks like it doesn't notice the constraint at all.