Macbook Pro w/ USB-C and multiple monitors occasionally swap non-main screens

displayhigh sierra

My Macbook Pro (15", 2017 model) running High Sierra has a multi monitor setup involving my laptop on the left, an external monitor to its right (and configured to be the main screen with the menu bar and dock), and another monitor to the right of that. Both external monitors (same brand and same resolution) are connected via HDMI cables that attach to Thunderbolt/USB-C plugs that go into an Elgato dock which then connects to the laptop via a Thunderbolt/USB-C cable.

I frequently will disconnect the laptop to go to a meeting and occasionally when I reconnect, my leftmost and rightmost screens become reversed, what I used to see on the laptop screen is now on the right external monitor. This goes for not only floating windows but also full screen apps. I then need to go into Mission Control to move the windows and full screen apps back to their preferred positions.

So firstly I want to know why this is happening and secondly how I can prevent that from occurring or a tool I can use to restore the windows as expected. I have seen some mention online that it could be related to which monitors are recognized by the computer first, and for sure for about 20 seconds after I plug in the cable I see a crazy dance of windows being resized and sometimes they all restore correctly. Could this be an issue with the dock or is it related to the OS and how it recognizes external monitors?

Thank you in advance!

Best Answer

So one "solution" is to unplug the USB-C cable from the computer and replug it in. I have at times had to do this several times before it picks up the correct configuration. Its totally anecdotal but I have found better results by unplugging and plugging it back in immediately before the computer has a chance to reorganize the windows on the laptop. So its not like the information is somehow corrupt or lost, it must be triggered by the order in which it recognizes the monitors.