Remove Datastore from Datastore Cluster in vCloud Director

Current Setup

vCloud Director :   9.1
vSphere:               6.5

We have a datastore cluster with 2 datastores inside.

vcd_ds_cluster1

As you can seee there are two datastores. saneql01-01 is the datastore I want to remove and is showing as empty

Note: The official recommendation was to "remove the tag in vCenter and then refresh the datastore policies wihin the VCD UI". This caused vCloud Director to lose visibility of the WHOLE datastore cluster. The correct process involves a couple of extra steps:

Process

In Vcenter

1) Select datastore (saneql01-01) -> Maintenance Mode -> Enter Maintenance Mode
2) Move datastore out of cluster (just by dragging is fine)
3) Select datastore (saneql01-01) -> Summary -> Tags -> Remove 

In VCD
4) Manage & Monitor -> vCenters -> Right click vcenter -> Refresh Storage Policies
5) vSphere Resources -> Storage Policies -> [check all showing correctly]