I just received my UD-ULTCDL from Amazon. I connected it up to my Samsung series 9 work laptop and then to two 24 inch monitors. It worked. The 4K port is set as my main Windows 10 monitor and the laptop is set to “Turn off the display” when lid is closed on power. This gives me two x 24 inch monitors.
From time to time the main screen stopped. Just went black. Nothing would bring it back. I installed the latest drivers, powered off, rebooted the PC, unplugged the Plugable, switched the monitors, replaced the HDMI cables. Then, I moved the USB-C cable (that runs power, both monitors and the hardwired LAN) and the main monitor went off. I wiggled it and sure enough the cable you supplied with the Pluggable is not making good contact with the box. I reversed the cable end to end and it still does it.
I do not know if this is the cable or the Plugable box. I do know this is a work computer and I do know that it needs to be fixed quickly please.
I look forward to your reply.