Failed to provision volume with StorageClass "default": Post https://vcenter.com:443/sdk: x509: certificate signed by unknown authority

Failed to provision volume with StorageClass “default”: Post https://vcenter.com:443/sdk: x509: certificate signed by unknown authority

Rancher ver 2.5.7

Unable to create persistent volume, status : pending

kubectl describe pvc mariadb-k8s-pvc

Name: mariadb-k8s-pvc
Namespace: default
StorageClass: default
Status: Pending
Volume:
Labels:
Annotations: volume.beta.kubernetes.io/storage-class: default
volume.beta.kubernetes.io/storage-provisioner: kubernetes.io/vsphere-volume
Finalizers: [kubernetes.io/pvc-protection]
Capacity:
Access Modes:
VolumeMode: Filesystem
Used By: mariadb-77b89c6cb6
Events:
Type Reason Age From Message


Warning ProvisioningFailed (x6 over ) persistentvolume-controller Failed to provision volume with StorageClass “default”: Post https://vcenter.com:443/sdk: x509: certificate signed by unknown authority

Any thoughts why PVC stuck at “pending” status, suggestions to resolve highly appreciated.