UD3900C4 USB Type-C only works when unplugged then plugged back in, and only 2 of the HDMI ports work

USB Docking Stations UD-3900
1

*Working on a Mac Studio M1 Ultra, 64gb ram, Sonoma 14.6.1.
*Everything is up to date.
*Display Link has successfully been installed and is the most current version.:

I’m working with the UD3900C4 dock.

When I boot up, the dock doesn’t register or appear. It’s powered on correctly, and physically connected correctly, but doesn’t appear or register.

IF I UNPLUG AND THEN REPLUG IN THE POWER SOURCE, THEN AND ONLY THEN DOES THE DISPLAY PORT APP WORK. Specifically, 2 of the monitor ports do in fact show up in the app as active, with their controls visible and listed and active. Note, the green light that i believe is supposed to show up does NOT show up at this point, even though 2 monitors appear to be active.

Beyond that, only 2 of the 4 HDMI ports seem to work (specifically port 1 and 2). Ports 3 and 4 do not work.

*Note: I have 6 total monitors that I would like to use. I AM able to successfully plug them in to my computer and they all work correctly when plugged in. Just not through the dock.

Please help : )

2

Hi there,

Thank you for reaching out. It looks like you submitted a ticket yesterday regarding the same issue. Your ticket number is 456073. Please reply to my email once you get the chance, and we will continue our communication through that channel.

There is much to cover here, but ultimately, the UD-3900C4 is not the docking station we recommend for your use case. While the UD-3900C4 is an excellent docking station, it is limited on macOS because Apple does not support DisplayPort Alt-Mode MST(Multi-Stream Transport) technology, which this docking station relies on to power the HDMI 3 and 4 connections. This docking station can support a maximum of three displays on macOS systems.

Given your desire to use six total displays, this may not be an ideal solution for your setup.

Thank you,

Adi
Plugable Technologies

3

Shoot. I wish I would have known that : /

Is there a docking station that will work for me that will supply 4 ports (or at least something that will supply more than 2)?