Some users have reported after macOS Big Sur version 11.1 and newer that their USB-C Triple Display Docking Stations may not be correctly detected by Apple’s MacBook Air, MacBook Pro, Mac Mini, iMac, and Mac Studio computers with Apple Silicon processors after being restarted, when powered on after being turned off, or after being in sleep mode and then woken up. Older Intel processor based Macs are not affected.
This issue affects the UD-ULTCDL (original version), UD-ULTC4K (original version), and UD-3900PDZ docking stations along with any connected USB 2.0 and 3.0 devices, including the two DisplayLink based video outputs, Ethernet, and audio controlled by the DisplayLink USB Graphics chipset. The primary USB-C DisplayPort Alternate Mode based video output and connected display should remain functional after reboot. Charging should also be unaffected.
For most users simply unplugging the docking station from the computer, waiting 10-15 seconds, then reconnecting the docking station will restore the functionality, if this does not help please try these additional steps to fully reset the docking station and computer:
- Unplug the dock from the Mac and unplug power from the dock. Please leave the dock disconnected until the final step.
- Fully shutdown the Mac. (On your Mac, click the "Apple" menu and select "Shut Down")
- After the Mac has shutdown, wait for 60-90 seconds, then turn the Mac back on.
- After logging back in, wait for an additional 30-60 seconds, then plug power back into the dock first and plug the dock into the Mac next (using the provided USB-C to USB-C cable the dock shipped with) and see if the behavior has improved.
We are hopeful this issue may be resolved by a future update to macOS but do not have a timeline for such a resolution. We will update this article periodically as we learn more. As of macOS 14.x Sonoma we are still seeing occasional reports of this issue.
If these initial troubleshooting steps do not help, please contact us at support@plugable.com and we'll be happy to assist you.