Hi guys (my first post)!

I'm having issues with my CalDigit USB-C HDMI Dock. Screen connected to the HDMI port next to the Thunderbolt 3 port experiences random flickering or stuttering when MacbookPro connected to the dock came from sleep state. Flickering seems to be triggered by mouse movement, see video:


Here's how the issue happens:

  1. Recently started from reboot or OFF state MacbookPro is connected to dock.
  2. Close lid to use in clamshell mode
  3. Use dock with both external displays without any issue.
  4. Disconnect MacbookPro from dock, and let it sleep/hibernate for about 5 hrs. (maybe less)
  5. Come back to dock and reconnect (did both ways; clamshell or open lid)
  6. Flickering issue starts to show on display connected to HDMI port next to Thunderbolt 3 port
  7. Moving the mouse (or trackpad) seems to trigger the issue sometimes (see video)
  8. Issue doesn't go away until MacbookPro is rebooted

Things I tried:

  • connected each screen to that one port and both experienced flickering (the screen connected to the HDMI port left to power supply did not flicker)
  • Reset NVRAM, SMC
  • disconnecting dock from power and reconnected
  • Disconnecting both HDMI monitors
  • "Detect Displays" in Settings
  • Changed resolutions/refresh rates
  • Mirror and un-mirror displays
  • bought 2 new HDMI that support 4ka t 60 cables and the issue persists.
  • new CalDigit dock unit (this is my second unit)


  • MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports) 2.3 GHz Dual-Core Intel Core i5
  • Big Sur 11.3.1 (20D91)
  • x2 Asus Displays VP239 HDMI 1080p @ 60GHZ
  • New HDMI cables that support 4k at 60GHZ
  • CalDigit USB-C HDMI Dock

Any ideas what it could be? I appreciate your help!!!!! 😩

1 Answer 1


I had the same issue. I installed the firmware update and restarted.
So far so good, maybe it will help you as well.


  • 1
    Sadly no firmware update for USB-C HDMI Dock yet Jun 28, 2021 at 17:45

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