When OpenStack is the platform, to have a predictable EgressIP for traffic going outside of the cluster, one needs to manually assign a floating IP to the reservation port created to represent the EgressIP. This is now unclear for the customers and a box explaining that should be added to the docs that explain assigning EgressIP to a namespace [1]. Something like:

When running on {rh-openstack-first}, to have a predictable egress IP for the traffic going through the main router and outside of the cluster, you need to assign a floating IP to the reservation port created in Neutron by OpenShift. The part will be named using the pattern `egressip-<ip>`, where `<ip>` is the egressIP assigned to the namespace. To create and attach the floating IP you need to call OpenStack API:

openstack floating ip create <external-network>
openstack floating ip set --port egressip-<ip> <floating-ip>

[1] https://docs.openshift.com/container-platform/4.12/networking/ovn_kubernetes_network_provider/assigning-egress-ips-ovn.html