SC4020 cluster volume - multi server access query

Hi All,

I am setting up an SC4020 to talk with 3 Hyper-V 2016 Server servers.  I am trying to create some shared areas so that all servers can read/write to them simultaneously, I've used the "Create server cluster" feature in DSM.

I can see the 3 servers connected to the volume but when I create a test file/directory on one of the servers, it is not showing up on the others...

Any pointers?  I have MPIO installed, etc.

Regards
Colin