Opening pod's terminal fails with "The terminal connection has closed" in OpenShift 4

Issue

• When trying to access pod's terminal from the web console, it doesn't work and shows the error "The terminal connection has closed"
• Trying oc rsh to any pod doesn't work either and shows an error calling a webhook:

$ oc rsh test-5f8cdbbb6f-f4hpk
Error from server (InternalError): Internal error occurred: failed calling webhook "validate-exec.devworkspace-controller.svc": Post "https://devworkspace-webhookserver.openshift-operators.svc:443/validate?timeout=10s": no endpoints available for service "devworkspace-webhookserver"