When you try to add the iSCSI Network Port Binding, there is a missing Adaptor in the Network port binding list
VMware ESXi
This is caused when the incorrect vmnic is associated with the uplink.
Example: When you see the port group for iscsi, the active uplink is uplink2, but the related vmnic physical adaptor is not assigned to uplink2 causing this adaptor not to be seen in Network port binding section under iSCSI storage adaptor
To Resolve:
For Distributed Switch:
1. Access vCenter distributed switch configuration
2. Navigate to the host's network adapter assignment
3. Reassign vmnics to correct distributed switch uplinks
Verify iSCSI binding:
1. Navigate to Storage Adapters > iSCSI Software Adapter > Network Port Binding
2. We should now see both adaptors