Disabling port-binding - grey out ticked box

I've configured an iSCSI over a dedicated connection and my setup, as far as I'm aware, does not include any port bindings. I explicitly want to avoid iSCSI port binding.

My settings are showing it ticked but greyed out.

Despite quite some search I cannot establish what this actually means. If it is "enabled" how do I disable it? If it is greyed out does this actually mean this option is not being used and therefore it is disabled?

Thanks.