Router-Default pods unschedulable on otherwise ready nodes [taint intolerance]

Issue

• One router-default pod will not schedule to ready nodes:
• Employing Infra nodes or attempting to schedule to worker nodes

$ oc get pods -n openshift-ingress:

NAME                             READY  STATUS   RESTARTS  AGE
router-default-69c44c6b94-t4hdw  1/1    Running  0         6d
router-default-84ff4c69cd-wrzxj  0/1    Pending  0         18m

• Ingress operator reports error about taint intolerance and node placements (despite one pod scheduling fine)
• May also see that neither pod schedules

$ oc get co/ingress -o yaml:

- lastTransitionTime: '2021-08-11T16:32:23Z'
    message: 'Some ingresscontrollers are degraded: ingresscontroller "default" is
      degraded: DegradedConditions: One or more other status conditions indicate a
      degraded state: PodsScheduled=False (PodsNotScheduled: Some pods are not scheduled:
      Pod "router-default-84ff4c69cd-jlkh7" cannot be scheduled: 0/9 nodes are available:
      3 node(s) didn''t match Pod''s node affinity, 3 node(s) had taint {node-role.kubernetes.io/infra:
      }, that the pod didn''t tolerate, 3 node(s) had taint {node-role.kubernetes.io/master:
      }, that the pod didn''t tolerate. Make sure you have sufficient worker nodes.),
      DeploymentReplicasAllAvailable=False (DeploymentReplicasNotAvailable: 1/2 of
      replicas are available)'
    reason: IngressControllersDegraded
    status: 'True'
    type: Degraded

• Replica sets are split into multiples and not unified:

NAME                          DESIRED   CURRENT   READY   AGE
ingress-operator-69c44c6b94   1         1         1       29h
ingress-operator-84ff4c69cd   1         0         0        4h