PLugging in 3900z disconnects another direct attached monitor

HI, just got a widescreen monitor and realised plugable 3900z doesnt support 3440 x 1440 resolutions. As a work around I am trying to do the following:

  • connect new widescreen monitor direct to laptop
  • connect another regular monitor (1920x1080), LAN and audio to the 3900z, which connects to the USB port of the laptop.

Without the 3900z plugged in the widescreen monitor works perfectly at 3440 x 1440. Once I plug the 3900z in, the widescreen monitor disconnects and the third monitor becomes connected.The system display shows 3 monitors (inc. the laptop monitor itself), but the widescreen shows as inactive.

Any ideas on how to resolve this?

Ideally I would have everything going through the 3900z but if it wont support a 3440 x 1440 resolution then I will connect it directly to the widescreen and use the 3900z for the 3rd standard monitor/LAN/Audio.


Hi Chris,

Thank you for contacting Plugable! I am sorry to hear that your UD-3900Z docking station is not functioning as expected, and would be happy to provide additional support.

To help diagnose the issue, may I ask you to please keep the dock and 1440p monitor connected to your laptop and everything still attached (even if not working as expected) and send us the output of our diagnostic utility PlugDebug? →

Once you have the logs, simply send an email to with the subject line of “Ticket 385425” so that we can prioritize that case and match it to this inquiry.

If you could provide your Amazon Order ID (or other proof of purchase) associated with your Plugable device, I would be happy to check on your warranty status as well.

Thank you for giving us the chance to help!

Plugable Technologies

Email with the logs and amazon receipt has been sent, let me know if anything else needed. Thanks

Hi Chris,

Thank you for letting me know!

I will go ahead and follow-up via the direct email thread going forward.

Plugable Technologies

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