Datastore clone cannot be mounted to newer version

Hi,

I have a case where older vmfs version cannot be mounted (maintain data) in the newer ESX version. My env : ESXi 5.5.0 build-2068190, my new env : ESXi 6.7.0 U1.

Both environment connected to a netapp storage (fas 3000).

We create a flexclone from a datastore which has been used in ESX 5.5. Then the flexclone mapped to the ESX 6.7

In the web client I can see the ESXi 6.7 reads the VMFS but failed to read the metadata, so the datastore cannot be mounted without format its content.

But if the flexclone mapped to the ESX 5.5, when adding the datastore, ESX 5.5 can read the metadata by showing options like datastore resignature, maintain or format.

Need advice/inputs.

Thanks.