kubernetes e2e tests fails with spec.configSource: Invalid value - testing

Question

We are running kubernetes(1.15.3) e2e tests via sonobuoy and 3 of them fail with the same error:
/go/src/k8s-tests/test/e2e/framework/framework.go:674
error setting labels on node
Expected error:
<*errors.StatusError | 0xc001e6def0>: {
ErrStatus: {
TypeMeta: {Kind: "", APIVersion: ""},
ListMeta: {SelfLink: "", ResourceVersion: "", Continue: ""},
Status: "Failure",
Message: "Node \"nightly-e2e-rhel76-1vm\" is invalid: spec.configSource: Invalid value: core.NodeConfigSource{ConfigMap:(*core.ConfigMapNodeConfigSource)(nil)}: exactly one reference subfield must be non-nil",
Reason: "Invalid",
Details: {
Name: "nightly-e2e-rhel76-1vm",
Group: "",
Kind: "Node",
UID: "",
Causes: [
{
Type: "FieldValueInvalid",
Message: "Invalid value: core.NodeConfigSource{ConfigMap:(*core.ConfigMapNodeConfigSource)(nil)}: exactly one reference subfield must be non-nil",
Field: "spec.configSource",
},
],
RetryAfterSeconds: 0,
},
Code: 422,
},
}
Node "nightly-e2e-rhel76-1vm" is invalid: spec.configSource: Invalid value: core.NodeConfigSource{ConfigMap:(*core.ConfigMapNodeConfigSource)(nil)}: exactly one reference subfield must be non-nil
not to have occurred
/go/src/k8s-tests/test/e2e/apps/daemon_set.go:170
kubectl get nodes -o yaml gives these fields and yes, we do have kubelet dynamic config enabled:
spec:
configSource:
configMap:
kubeletConfigKey: kubelet
name: kubelet-config-1.15.3-1581671888
namespace: kube-system
[cloud-user#nightly-e2e-rhel76-1vm ~]$ kubectl get no nightly-e2e-rhel76-1vm -o json | jq .status.config
{
"active": {
"configMap": {
"kubeletConfigKey": "kubelet",
"name": "kubelet-config-1.15.3-1581671888",
"namespace": "kube-system",
"resourceVersion": "508",
"uid": "71961ed7-2fff-41f5-80b7-78167fb056fc"
}
},
"assigned": {
"configMap": {
"kubeletConfigKey": "kubelet",
"name": "kubelet-config-1.15.3-1581671888",
"namespace": "kube-system",
"resourceVersion": "508",
"uid": "71961ed7-2fff-41f5-80b7-78167fb056fc"
}
},
"lastKnownGood": {
"configMap": {
"kubeletConfigKey": "kubelet",
"name": "kubelet-config-1.15.3-1581671888",
"namespace": "kube-system",
"resourceVersion": "508",
"uid": "71961ed7-2fff-41f5-80b7-78167fb056fc"
}
}
}
What are we missing?
Thanks.