How to make 3 external monitors without one of them mirroring on a 13 inch MacBook Pro 2017

[DrAnna2020]

I have a Mac Book Pro 2017 two Thunderbolts 3 ports. I purchased the Plugable usb-c 4k docking station and two displayport HDMI 2.0 active adapters. I have plugged the display ports with two monitors and one monitor to the HD post in the back of the docking station. Displaylink is active.

This is the problem. I go to arrange my displays in settings and two displays behave as one. While there are 4 displays including the Built-in Retina Display, View Sonic Monitors x2476 (1), View Sonic Monitors x2476 (2), View Sonic Monitors x2476 (3), and View Sonic Monitors x2476 (4). It will only recognize three of them which explains the mirroring.

Can someone please help?

[Joshua_H]

Hello Anna,

Thank you for contacting Plugable support! Sorry to hear about this issue. I’d be more than happy to assist you.

We don’t officially support macOS with our DisplayLink-based docking stations and USB graphics adapters, as there have been historical driver incompatibilities in the past. (We do mention this on our website and product listing, but realize it can be easy to miss.) That being said, there has been significant progress made by DisplayLink with macOS Mojave and Catalina with an updated driver and for most of our customers report good results with this setup, and if this trend continues we hope to change macOS to a supported platform. However, please note that for the time being we may be limited in the support we can provide should further issues arise.

Since things are mostly working, just that two displays are being mirrored, it’s likely driver or settings related in some way and shouldn’t be too difficult to fix. To try and resolve this, I have a few questions:

1. What version of macOS is your MacBook Pro running?

2. Does macOS present you with the option to disable mirroring in the display arrangement settings?:

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Please don’t hesitate to let us know of other questions.

Thanks again for contacting Plugable support and best wishes!

Joshua Henry

Senior Engineer | Product Owner
Plugable Technologies

[DrAnna2020]

Thank you for trying to help me.

macos catalina version10.15.5

Any guidance will be greatly appreciated

[DrAnna2020]

Please advise

[Joshua_H]

Hi Anna!

We’re still investigating this issue, it’s not something we’ve encountered before. I’ve received your direct email to our support and have sent a reply there with more information and some instructions to gather some diagnostics data to further our investigation.

Thanks!
Josh

For anyone else who may encounter this issue, I will update here with any conclusive steps to fix this issue.