The computer is a Surface Pro2 running Windows 8.1 with the latest Pluggable display drivers. I replaced my monitor with a new 4K monitor from Dell (S2817QR). To make that work, also replaced my Pluggable UD-3900 with a UD-5900.
The UD-5900 sorta works. It will drive the monitor via HDMI if I don’t plug any USB devices directly into the UD-5900. If I plug any non USB 3 devices into the UD-5900, the monitor will go dark, but the USB devices will work. I was able to plug the monitor’s USB3 cord into the UD-5900 and then use the monitor as a hub for the devices.
Have I got a defective UD-5900 are is it working as designed?