Windows OS cannot find the configured vSAN ISCSI target.
Confirm the vSAN iSCSI targets exist by navigate to the vSAN cluster in the vSphere Client, go to the Configure tab, and then select vSAN > iSCSI Targets. This will display a list of all configured iSCSI targets for that cluster.
VMware vSAN [All Versions]
The vitd service, or the vSAN iSCSI target service, is responsible for providing iSCSI target functionality within the vSAN environment.
Restart the vitd service ensuring all hosts have proper communication to the vSAN iSCSI targets by running /etc/init.d/vitd restart on all hosts.