This should put a bit more light on your issue:
https://support.microsoft.com/en-us/help/870964/file-shares-on-iscsi-devices-may-not-be-re-created-when-you-restart-th
NFS shares dissappear after reboot of Windows server
This should put a bit more light on your issue:
https://support.microsoft.com/en-us/help/870964/file-shares-on-iscsi-devices-may-not-be-re-created-when-you-restart-th