In [1], the configuration variable "edpm_ovn_bridge_mappings" has no type definition, leading to a misconfiguration if a string is passed. This variable must be a list of strings.

The following configuration example can be added in the section 5.2, in the OpenStackDataPlaneNodeSet example:
edpm_ovn_bridge_mappings: ["datacentre:br-ex"]

[1]https://docs.redhat.com/en/documentation/red_hat_openstack_services_on_openshift/18.0-beta/html-single/adopting_a_red_hat_openstack_platform_17.1_deployment/index#pulling-configuration-from-tripleo-deployment_reviewing-configuration