Thanks for posting! I appreciate the troubleshooting you’ve already done as well as the details you provided.
Networking issues such as these can often be quite complex and difficult to isolate as different factors vary from environment to environment. The first thing I’d like to check is that your UD-3900 docking station is connected to a USB 3.0 port on your laptop, as well as that you are using the included USB 3.0 cable that came in the device package. If you aren’t sure, please let me know the specific make and model of your laptop and I’d be happy to look it up for you.
Pending this confirmation, I’d like to request some logs from your system to investigate further. Could you keep the dock connected to your system (with Ethernet cable connected to the dock), then navigate to our PlugDebug tool and follow the instructions there? After the ZIP file is created on your Desktop, please send it to us at email@example.com with “Ticket #237617” as the subject line.
Thanks for your patience while we work to help!