Cluster operator network is degraded in RHOCP 4

Issue

• Cluster operator network is not available.
• Network Operator degraded with below error.

$ oc get co
NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
authentication                             4.10.19   True        False         False      17d     
baremetal                                  4.10.19   True        False         False      43d     
cloud-controller-manager                   4.10.19   True        False         False      43d     
cloud-credential                           4.10.19   True        False         False      43d     
cluster-autoscaler                         4.10.19   True        False         False      43d     
config-operator                            4.10.19   True        False         False      43d     
console                                    4.10.19   True        False         False      43d     
control-plane-machine-set                  4.10.19   True        False         False      43d     
csi-snapshot-controller                    4.10.19   True        False         False      43d     
dns                                        4.10.19   True        False         False      43d     
etcd                                       4.10.19   True        False         False      43d     
image-registry                             4.10.19   True        False         False      25d     
ingress                                    4.10.19   True        False         False      43d     
insights                                   4.10.19   True        False         False      43d     
kube-apiserver                             4.10.19   True        False         False      43d     
kube-controller-manager                    4.10.19   True        False         False      43d     
kube-scheduler                             4.10.19   True        False         False      43d     
kube-storage-version-migrator              4.10.19   True        False         False      25d     
machine-api                                4.10.19   True        False         False      43d     
machine-approver                           4.10.19   True        False         False      43d     
machine-config                             4.10.19   True        False         False      43d     
marketplace                                4.10.19   True        False         False      43d     
monitoring                                 4.10.19   True        False         False      43d     
network                                    4.10.19   True        False         True       43d Error while updating operator configuration: could not apply (k8s.cni.cncf.io/v1, Kind=NetworkAttachmentDefinition) multus-test/backupnet: ApplyObject of (k8s.cni.cncf.io/v1, Kind=NetworkAttachmentDefinition) multus-test/backupnet was unsuccessful: namespaces "multus-test" not found    
node-tuning                                4.10.19   True        False         False      43d     
openshift-apiserver                        4.10.19   True        False         False      43d     
openshift-controller-manager               4.10.19   True        False         False      43d     
openshift-samples                          4.10.19   True        False         False      43d     
operator-lifecycle-manager                 4.10.19   True        False         False      43d     
operator-lifecycle-manager-catalog         4.10.19   True        False         False      43d     
operator-lifecycle-manager-packageserver   4.10.19   True        False         False      43d     
service-ca                                 4.10.19   True        False         False      43d     
storage                                    4.10.19   True        False         False      43d