In the docs under "4.4. Creating a manifest object that includes a customized br-ex bridge"[1] the example NNCP file has hardcoded values that may not always be correct. Specifically it hardcodes 169.254.169.2 which corresponds to the SDN internalMasqueradeSubnet value which we now set to 169.254.0.2 as well as the ipv6 route which for me is fe80::/64 

[1] https://docs.redhat.com/en/documentation/openshift_container_platform/4.19/html/installing_on_bare_metal/bare-metal-post-installation-configuration#creating-manifest-file-customized-br-ex-bridge_bare-metal-postinstallation-configuration

Doc shows the NodeNetworkConfigurationPolicy to be:

...
    - name: br-ex
      type: ovs-interface
      state: up
      copy-mac-from: enp2s0
      ipv4:
        enabled: true
        dhcp: true
        auto-route-metric: 48 
        address:
        - ip: "169.254.169.2"
          prefix-length: 29
      ipv6:
        enabled: true
        dhcp: true
        auto-route-metric: 48
        address:
        - ip: "fd69::2"
        prefix-length: 125