Failover cluster in windows2016 under simplivity has issue with the shared disk, for example anything written on "shared disk cluster" owned under node01 cannot be reflected on node02 while takenover by the node02.
Looked into it thoroughly and tested all option to resolve the issue, looks to me now that HP cluster configuration itself have shared disk problem.
HP need to see this issue, create any test file in cluster shared disk and write some files from node1 and then for test purpose node1 need to be switchover to node2 and see if the file written by node1 is visible through node2.
Does the cluster validation give you All success green marks? also is that shared disk a SAN? ISCSI or Fiber?
I had setup a cluster fail over VM, when node 1 is the owner of the VM and the disks, those disks will have "reserved" status for other nodes, so there won't be any file corruption and so if node 1 writes to the disks, those changes should be visible to other disks. i was using a nested virtualization using ISCSI SAN (all virtual) on Windows Server 2019 Hyper-V.