

My particular monitor has a USB-C port that supports alternate mode for video as well.

It does also support DP alternate mode for USB-C though.

The TB3 port on the back is actually on a seperate bus. Even though it is mirrored, the second does not show in the System Profiler. The macOS will not even recognize the second monitor is attached. When two monitors are connected to any two of those ports the macOS will only recognize 1 monitor and then mirror the display of that monitor to the second. What I just figured out after looking at how the ports are attached in the dock is that the the USB-C, DP1 and DP2 ports are all on the same bus and hub. I have the early 2016 MacBook Pro with TB3 Intel Iris 550. Business PCs, Workstations and Point of Sale Systems.Printer Wireless, Networking & Internet.DesignJet, Large Format Printers & Digital Press.Printing Errors or Lights & Stuck Print Jobs.Notebook Hardware and Upgrade Questions.
