Ivanildo,
First, let us know how the Isolation Response is configured for your cluster, take a look here for additional details about Isolation Response options: vSphere 5 HA - Isolation Response which one to pick? - Yellow Bricks
And since your "network disconnect" host still have access to the storage, the Datastore Heartbeat may help master hosts of the cluster identify the state of the host, see: Datastore Heartbeating and preventing Isolation Events? - Yellow Bricks
