Heartbeat Datastore list Empty:

Heartbeat Datastore list Empty:

I have one shared datastore. In Vsphere HA, if I click on Heartbeat Datastore I see by default this option selected :
"Use datastores from the specified list and complement automatically if needed"

I am not sure why the above option is by default though it makes sense to me that the option below should be by default:
"Automatically selected datastores accessible from the Hosts"

I also do not see the Shared Datastore listed.

Any help ?

thank you