Upgrade stuck in worker node Not Ready in OCP 4

Issue

• The upgrade is stuck with many workers not upgraded, and one of them is permanently in Not Ready status.
• Doing oc debug node/<node-name> does not work.
• There are no containers running inside the node.

> oc get clusterversion
version  4.7.19   True       False        1m24s  Error while reconciling 4.7.19: the cluster operator network is degraded

> oc get nodes
nodename.example.com  NotReady  worker  187d  v1.20.0+df9c838

> systemctl status kubelet
E0804 13:50:37.494428    1906 kubelet.go:2265] node "myopenshift.example.com" not found
E0804 13:50:37.594545    1906 kubelet.go:2265] node "myopenshift.example.com" not found