UD-ULTC4K + macbook pro (lid closed)

I just plugged everything in and installed the drivers (and allowed permission to it in security preferences). So far everything is working great. I’ve got 2 displays hooked up via display port. No issues with the laptop going to sleep even with the lid closed since it is getting power through the same USB-C port.

My only issue is the laptop’s display not going to sleep with the laptop’s lid closed. I’m really picky about my monitors having the same resolution & size, so I keep the laptop lid closed. I read some earlier posts about how people just pull the laptop’s screen to the right or left and just ignore it. I set one of my external displays as the ‘main’ display with the menu bar there. I understand the difference between mac and windows here and why this is happening.

I still worry about windows of messaging apps popping up on my laptop’s display and I won’t notice it. Plus I’m just causing unnecessary burn-in with it on all the time but nothing changing on the screen. Any recommendations on how to solve this? Even if it’s a round-about way with 3rd party software.

Hello Amr, thanks for posting and I’ll be happy to help.

Unfortunately, this is a known issue with DisplayLink adapters and dock within MacOS/Mac OS X. DisplayLink (the manufacturer of the chip within our dock and author of the software) has a knowledge base article here –>https://support.displaylink.com/knowl… that speaks to this.

The monitors connected to the two DisplayPort output ports are not seen by MacOS as an external monitor the same way they would be if connected directly. If your monitors have an HDMI port you can use the HDMI output port on our dock to connect them which is based off of DisplayPort Alternate Mode. This would be like using a USB-C to HDMI adapter to connect the monitor directly to the internal graphics processor. Once a screen is directly connected via this method the Clam Shell Mode should then take effect. The HDMI port is limited, however, to 4K@30Hz resolutions and I just wanted to mention this in case 4K@60Hz is desired on your monitors.

Unfortunately, I am not aware of a 3rd party software workaround for this issue.

Thank you,

David W.
Plugable Technologies

Thanks for the details! I also came across that page from displaylink. The info about using HDMI is helpful. The monitors I have now don’t have an hdmi port, so I ordered an hdmi -> dvi adaptor. Until it comes in, I’m hooking up one monitor directly (usb-c to displayport) and the display goes off now. (2 connections better than 4 that I usually have to do).

I’m not concerned about 4k right now. I bought this as a (hopefully) future-proof investment even though I’m using just 1080p displays for now.

Hi Amr, thanks for the reply and glad to hear that this workaround is sufficient. Hopefully this can be addressed in future DisplayLink driver revisions or MacOS updates.