I am using a 2019 13-inch MacBook Pro (2 Thunderbolt ports) with a dual monitor setup. I typically close my MacBook lid so the 2 monitors are my main monitors. However, with the lid closed. My MacBook only sees 1 monitor; both monitors show the exact same screen (so they mirror).

I've read online that typically this is caused by your dock. But I have no clue which dock to use if that's the case since my current dock: Club-3D USB Type C 3.2 Gen1 Triple Display Dynamic PD Charging Dock.

It works fine with a Windows laptop, connecting both screens and extending them.

I'm hoping since the exact same setup does work on Windows that there's a software fix.

If not, I'm curious to find out which dock to use that does also supports Mac.

1 Answer 1


The specifications here state that this dock is an MST device. Only SST is supported by macOS. This is a current limitation of macOS.

You need a Thunderbolt dock.

  • Thanks Marc, that helps a lot. I was unaware of that. I will look up the difference between SST and MST and get myself a SST Dock. :)
    – user484266
    Commented Jan 18, 2023 at 19:14

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