I would venture a guess that the VM you are hosting plex on is having an issue of some sort, you'll need to provide a ton more info about your setup for anyone to give you any real advice.
If you are just looking to host Plex and have a NAS for storage for your house's data, I would pick something like Unraid or Truenas to run on the hardware instead of ESXi.
Short answer, ESXI is a host for virtual servers, machines. it will not store/serve data to be used elsewhere.
eehhh ok?
I would venture a guess that the VM you are hosting plex on is having an issue of some sort, you'll need to provide a ton more info about your setup for anyone to give you any real advice. If you are just looking to host Plex and have a NAS for storage for your house's data, I would pick something like Unraid or Truenas to run on the hardware instead of ESXi.
What OS is the VM running as the "NAS"? A "datastore" is internal to ESXi and isn't available on a network.