aws-ebs-csi-driver-operator-master-e2e-operator flake a lot, we were not able to merge a PR for 5 days:

https://testgrid.k8s.io/redhat-openshift-ocp-release-4.6-informing#release-openshift-ocp-installer-e2e-aws-csi-4.6
https://prow.ci.openshift.org/pr-history/?org=openshift&repo=aws-ebs-csi-driver-operator&pr=70

They typically fail because a test gets "connection refused" from API server. Using https://prow.ci.openshift.org/view/gs/origin-ci-test/pr-logs/pull/openshift_aws-ebs-csi-driver-operator/70/pull-ci-openshift-aws-ebs-csi-driver-operator-master-e2e-operator/1290552613552525312 as an example:

fail [@/k8s.io/kubernetes/test/e2e/e2e.go:262]: Unexpected error:
...

    Get https://api.ci-op-5wcn99xm-79224.origin-ci-int-aws.dev.rhcloud.com:6443/api/v1/nodes?fieldSelector=spec.unschedulable%3Dfalse&resourceVersion=0: dial tcp 54.236.162.103:6443: connect: connection refused
occurred

From logs and events of this CI job:

1. Installation completes:
time="2020-08-04T06:50:09Z" level=info msg="Install complete!"

2. e2e tests start
openshift-tests version: v4.1.0-3029-g5279aaf
I0804 06:50:12.796634     235 test_context.go:427] Tolerating taints "node-role.kubernetes.io/master" when considering if nodes are ready
...

3. *something* restarts API servers
Event at 06:50:21
Status for clusteroperator/kube-apiserver changed: Degraded message changed from "NodeControllerDegraded: All master nodes are ready" to "NodeControllerDegraded: All master nodes are ready\nStaticPodsDegraded: pod/kube-apiserver-ip-10-0-192-228.ec2.internal container \"kube-apiserver\" is not ready: PodInitializing: \nStaticPodsDegraded: pod/kube-apiserver-ip-10-0-192-228.ec2.internal container \"kube-apiserver-cert-regeneration-controller\" is not ready: PodInitializing: \nStaticPodsDegraded: pod/kube-apiserver-ip-10-0-192-228.ec2.internal container \"kube-apiserver-cert-syncer\" is not ready: PodInitializing: \nStaticPodsDegraded: pod/kube-apiserver-ip-10-0-192-228.ec2.internal container \"kube-apiserver-check-endpoints\" is not ready: PodInitializing: \nStaticPodsDegraded: pod/kube-apiserver-ip-10-0-192-228.ec2.internal container \"kube-apiserver-insecure-readyz\" is not ready: PodInitializing: "

4. Things start failing:
Aug 04 06:51:21.347 W ns/openshift-apiserver deployment/apiserver reason/ConnectivityOutageDetected Connectivity outage detected: kubernetes-apiserver-endpoint-10-0-192-228-6443: failed to establish a TCP connection to 10.0.192.228:6443: dial tcp 10.0.192.228:6443: connect: connection refused (2 times)

5. And ultimately, the tests fail at 06:51:33.414 too:
Get https://api.ci-op-5wcn99xm-79224.origin-ci-int-aws.dev.rhcloud.com:6443/api/v1/nodes?fieldSelector=spec.unschedulable%3Dfalse&resourceVersion=0: dial tcp 54.236.162.103:6443: connect: connection refused
occurred

I do not know *why* is API server restarted, this event looks interesting:

06:51:58	openshift-kube-apiserver-operator	kube-apiserver-operator-installer-controller	
NodeCurrentRevisionChanged   Updated node "ip-10-0-192-228.ec2.internal" from revision 4 to 6 because static pod is ready

Was the installation reported to be completed too early? Upstream e2e tests (incl. conformance) don't retry on failure and they expect the cluster is stable.