Introspect fails with `No Hypervisor matching` error after undercloud hostname change in Red Hat OpenStack Platform 13

Issue

Introspect fails with No Hypervisor matching error after undercloud hostname change in Red Hat OpenStack Platform 13

Attempts to add new ironic nodes to an existing undercloud resulted in half of the nodes failing to be detected and added to nova.

Ironic API returned all of the newly added nodes when called by the driver, but half of the nodes were not returned to the compute manager by the driver.

This resulted in nova introspection succeeding in theory, but just before returning success to the user, nova deleted the hosts from its database.

There was only one nova-compute service managing all of the ironic nodes of the all-in-one typical undercloud deployment.

This happened after a change of hostname of the Director node from something containing uppercase letters to the same name but all lowercase.