This problem usually happens on computer with multiple network inerfaces (Ethernet, Wireless, etc.) There are two ways to resolve this issue, one is more permanent by adjusting the "network metric"; the other is to adjust the network interface option in DS Manager.
Adjusting the Network Metric
If your computer has multiple active network interfaces (Ethernet, WiFi, VPN, etc.), then sometimes windows will force the auto-discovery packet only to be sent out of the first interface in the list. This list is based on how Windows assigns the order, and the way to reorder manually is by adjusting what's called a "metric."
1. Open Command Prompt and type: route print - you will see a list of active routes, the last column displaying their "metric." Lower metric routes are preferred over higher ones.
2. Open the Network Adapter Properties (Control Panel > Network and Internet > Network Connections > right-click on adapter and choose Properties)
3. Open the properties of Internet Protocol Version 4 (TCP/IPv4).
4. Click on Advanced.
5. Un-tick "Automatic Metric" and set the interface metric to a number.
6. Hit OK until you close the Network Adapter properties.
7. Repeat steps 2-6 for your other network adapter(s) choosing different metrics. Remember lower metrics are preferred over higher ones.
Check the new metrics in Command Prompt by typing: route print
Adjusting DS Manager Network Interface
Open DS Manager and select File > Network Interface and select the network interface that your Device Server is connected to. This will limit all communication from DS Manager to go through the selected network interface.