The error shown when it fails to connect doesn't indicate a problem with LabVIEW in any way. It just states that it can't find anything on the network to connect to.
Generally when you use code to connect to something on the network, you want to make it so it either connects to a list of IP addresses or hostnames, or it uses some form of network discovery. Your code appears to be using the network discovery approach.
I would look into two different things:
First, see if there's any alternate methods you can use to get a list of network controllers, such as specifying addresses instead of just hoping that the network discovery works well.
Second, check the documentation or contact the vendor to see if they can give you details on what it takes for a network controller to be "discovered". It could be that you need to relax the firewall on your system, or it only looks on certain network adapters, or that there's a service that runs in the background that you need to configure, or that the controllers have been marked as "reserved" by a different host, or any number of other things.
