Catalina on Mac Mini Issue

[cshook58]

I am running catalina on a late 2012 mac mini and experience an odd issue where if I try to run 3 monitors 1 from hdmi or thunderbolt port on the mac and 2 from my DisplayLink device (Startech USB3SDOCKDD). With this configuration I get display on all 3 monitors but one of the DisplayLink monitors is a mirror of the monitor plugged into the Mac. When I view the display preferences it shows 3 displays, when I click on the 1st Display link monitor the red outline shows, when I click on the on attached do mac I get red outline on it and the other monitor plugged into the usb dock, and when I click on the 3rd display nothing gets the red outline.

I tried with 1 monitor plugged into the HDMI on the mac, 1 plugged into the thunderbolt on the mac, and 1 plugged into the usb dock and the 3 displays operate separately as expected.

This dock with the same drive works fine on my mac book pro.

Any help would be greatly appreciated and I can post any screen caps that my help but don't want to post a bunch of images without knowing what will be helpful diagnosing this issue.

[KatarzynaCzaja]

Hello,

Please try those steps:


Go to System Preferences -> Display Settings -> Arrangement Tab
Select option to turn off mirroring
Press and hold 'Option' key and drag one of the mirrored monitors away from the other.


Cheers,
Katarzyna

[cshook58]

Thanks Katarzyna, but that did not work. How ever on a whim I trying placing the white bar that indicates the main display on the display that would not highlight when viewing the arrangement and I get 3 independent display, but as soon as I move that bar to one of the other monitors I get the mirroring issue again.

This is not ideal but will work for now, I am happy to provide any screen shots or logs that may help resolve this issue.

[KatarzynaCzaja]

Hello,

Do you know what version of the driver do you have installed on your PC?

In case you are not sure please make sure that you use the newest one available on our website: https://www.displaylink.com/downloads/file?id=1552

Thank you,
Katarzyna