Affected VM is running on Standalone or Clustered ESXi?
Which app type VM belongs to? SQL or vHANA or standard Windows VM?
What Disk size of VM? Is it only one snapshot of VM or multiple snapshots of VM?
What kind of Datastore do you use? and do you have additional Datastores attached to ESXi host?
During VM snapshot creation, did you marked option snapshot with RAM or not?