No monitors on restart/start up

Hello. I have a 2020 M1 Mac Mini. I purchased the UD3900UDZ to use 3 monitors, One being for video output. So I’m using HDMI 2 & 3 on the dock for my desktop monitors and the HDMI on the Mac Mini for the video out. If I shut the computer down and then start it up or if I just restart the computer the monitors don’t come up unless I do the whole reset on the docking station. After I do that it works flawlessly. Is there a setting I’m missing or something? Thank you in advance.

Hi,

Thank you for contacting us, I am sorry this is not working as expected and I am happy to help!

I would like to start by getting some additional information to help narrow down the specific cause of this behavior, may I ask the following?

  1. Is this an Apple M1 based Mac Mini, or the Intel Mac Mini?
    1. Please let me know the specific model and year of the Mac Mini
    2. Please let me know the specific version of macOS running on this system
    3. Apple Menu > About this Mac will have both details.
  2. After restarting the computer and logging into the desktop, is the “DisplayLink Manager App” running? This icon ( underlined in red ) should be shown in the macOS top bar, please let me know if you do not see the icon
    1. When the displays are not detected, please also click on the DisplayLink icon, and from the drop down, let me know the following:
      1. Does it show the “Monitors Detected” or “No Monitors Detected” at the top?
      2. At the bottom, what is the DisplayLink Manager Version, for example 1.2.0, or 1.4.0?
  3. Are USB devices connected to the docking station ( for example a keyboard or mouse ) being detected when the computer is restarted, or are all of the docking station’s functions and connections inactive until reset?
  4. When you are resetting the docking station, are you simply unplugging and then re-plugging the USB-C cable from the docking station to the computer, or do you have to also unplug power from the docking station and then reconnect the power supply?

Thank you for these additional details, they will help to narrow down what may be causing this behavior and our next steps.

Pat

support@plugable.com

1.) It is an 2020 M1 Mac Mini 16 Gb Ram 2 Tb storage. It is running OS11.4.
2.) When I log into the mac, Yes the icon is up there. If I do not restart it, it does not show any monitors detected. It is Version 1.4
3.) I am unsure if the USB ports are working or not. I don’t have anything connected to them as of yet. I use the docking station mainly for the monitors at the moment.
4.) The first time I was able to unplug an HDMI from the station and plugged it back in then the two monitors came up. The next time I had the Mac Mini shut down and when started, I had to take one of the monitor HDMI cables out and plug it into the HDMI of the Mac Mini to log in then I had to unplug everything and then unplug the power cord and plug it all in then it worked properly.

I would like for the Monitors to be able to come up when I start my computer. Is this not possible with this docking station?

Hi,

Thank you for the additional details!

I would like for the Monitors to be able to come up when I start my computer. Is this not possible with this docking station?

This is the expected behavior and what we have seen in testing this model of docking station with all M1 systems so far.

1.) It is an 2020 M1 Mac Mini 16 Gb Ram 2 Tb storage. It is running OS11.4.

We have had a few similar reports from users with macOS 11.4 which may indicate a regression in this macOS release, however we have been unable to replicate this on our test system with this model of docking station.

2.) When I log into the mac, Yes the icon is up there. If I do not restart it, it does not show any monitors detected. It is Version 1.4

Most likely this indicates the computer is failing to properly detect the docking station, which could be either a regression in the macOS 11.4 release, a compatibility problem with a connected display, or possibly a hardware fault.

4.) The first time I was able to unplug an HDMI from the station and plugged it back in then the two monitors came up. The next time I had the Mac Mini shut down and when started, I had to take one of the monitor HDMI cables out and plug it into the HDMI of the Mac Mini to log in then I had to unplug everything and then unplug the power cord and plug it all in then it worked properly.

The Mac Mini requires one display controlled directly by internal graphics card to initially display, this can be either connected to the built-in HDMI output, or to the docking station’s HDMI 1 output port. The docking station’s HDMI 2 and HDMI 3 outputs are controlled by the DisplayLink software and are automatically setup as secondary displays at startup and login.

Based on the above behavior I would like to get some additional details directly from the computer to see how the docking station is being detected.

After next restarting the computer, when the docking station is not detecting correctly, please keep the dock connected to the computer with monitor (excepting one) connected to the docking station (even though they are not working) and attach the output of our diagnostic utility PlugDebug ( http://plugable.com/support/plugdebug ) to an email to ‘support@plugable.com’ with the subject line ‘Ticket #347164 - Attention Pat’ as this will allow us to examine some log files from your system to help determine the next steps.

Thank you for these additional details, I look forward to your reply email.

Pat
support@plugable.com

I will do the PlugDebug this Friday evening when I can get back to it. I did switch the HDMI to 1 and 2 then restarted the computer and it still did not come up. I had to just unplug the power to the docking station and plug it back in then the one Monitor came up for me to be able to log in and then the second monitor came on after log in.

Hi,

Thank you for replying back, I look forward to receiving the log file and taking a look at this issue in more detail.

Additionally, are the two HDMI displays connected to the docking station connected with HDMI cables longer than 9ft/3m, or any HDMI adapters, splitters, or HDMI signal boosters, range extenders, or HDMI to Ethernet adapters?

Thank you,

Pat
Plugable
support@plugable.com

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