I have an HP laptop, using the laptop monitor and 2 HDMI monitors- One connected through the PC’s HDMI port and the other through USB and Display link adapter. This has worked fine for years.
This morning Only one external monitor will work at a time. It defaults to the display link monitor, but the HDMI port will be come active if the USB is unplugged.
Also when all are plugged in the display link manage sees 3 monitors, but 1 is grayed out
Kurt also reached out to us directly for help via support@plugable.com and the cause in this instance was Windows marking a display as ‘Disconnected’.
The solution in this was to change the ‘Disconnected’ display to ‘Extend’. From my direct instructions:
"May I ask you to double-check within the Display Settings application (available via right-clicking on an empty space of your desktop), under the ‘Multiple displays’ section, that each monitor is set as an Extension of your desktop? (you will have to click on each monitor number to check the setting for each one).
In other words, we don’t want Windows marking any of them as ‘Disconnected’ (Windows 10 seems to do this on its own from time to time). I also made a short video that shows how to check and change this if you need it, here -> https://youtu.be/irAUYfdTp4I"
Bob
Plugable Technologies
www.plugable.com/support