Dock only working with one screen


MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports)
macOS Mojave Version: 10.14.4

I have installed, uninstalled and installed the mac drivers. I have 2 HDMI cables connected to the dock and using the supplied USB-C cable am connecting the the computer. The 4K port works but the second HDMI does not get detected at all. If I connect an additional HDMI to USB-C adapter the second display is detected and works as expected.

I have 2 HP E223 displays both using HDMI Cables. Also tried DVI to VGA adapter with the same results.


Hi There,

Thank you so much for reaching out to us, I am sorry to hear that you are running into this issue, but I would be more than happy to assist.

Based on the description of the issue, it looks as if you are utilizing our UD-ULTCDL, which is currently not compatible with macOS, due to incompatibilities and performance related issues with DisplayLink based devices (the 2K HDMI port and DVI port on the dock). The 4K HDMI port utilizes a feature of USB-C/Thunderbolt 3 called Alt-Mode (similar to the USB-C to HDMI cable you utilized) and this is most likely why this is the only port that is working properly.

If you head into System Preferences > Security > Extensions, do you see the “DisplayLink” driver listed in any of the options in order to unblock or allow the driver to be utilized?

Thank you for your time,
Product Owner & Technical Support


That option is not on my mac


But either way 2 screens is not an option for this model correct?


Hi There,

Thank you so much for looking for this setting. IF you do not see the setting inside of “Extensions” you may need to check inside of System Preferences > Security and Privacy for a notification that GateKeeper is blocking the extension (it should show a button to “Allow” the DisplayLink driver to be activated).

We do not support this particular dock with multiple displays inside of OBS due to performance and compatibility related reasons, but DisplayLink does provide a driver for macOS, and we have seen some customers successfully utilize more than one display with this dock and macOS, but it is inconsistent, and one of the main reasons why we mark it as incompatible. We make sure to point out this incompatibility on both the Amazon Listing, and on our individual product pages.

Please let me know if you are able to get everything working correctly, or if you have any additional questions or concerns, and I would be more than happy to assist.

Thank you for your time,
Product Owner & Technical Support


Hi Everyone,

We attempted to provide additional information regarding the compatibility of this dock on the customers operating system, but have not received any additional response back. If the customer has any additional questions or concerns, or any individual customer experiencing the same issue, please feel free to reach out to us directly at

Thank you for your patience,
Product Owner & Technical Support

closed #7