16-inch MacBook Pro thinks monitor is still connected after unplugging the monitor.

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Level 1

87 points

16-inch MacBook Pro thinks monitor is still connected after unplugging the monitor.

I've been having issues with the connection between my monitor and my 16-inch MacBook Pro (https://discussions.apple.com/thread/251377138).

Today I noticed that the 16-inch MacBook Pro sometimes shows that the monitor is still connected (e.g., in display settings) even after I've unplugged the monitor (screenshot below).

To get the MacBook to realize the disconnection, I have to plug and unplug the monitor until the MacBook Pro to acknowledges the disconnection.

This is leading to frustration problems (e.g., unwittingly making changes to a document that is not pictured on the MacBook because the MacBook thinks that my cursor is on another, imaginary display).

I don't have time to babysit display preferences every time I disconnect to see if the MacBook acknowledges the disconnection.

So how do I make sure this unacknowledged disconnect stops happening?

MacBook Pro with Touch Bar

Posted on May 26, 2020 7:47 AM

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Answer 1

xser Author

Level 1

87 points

May 26, 2020 11:43 AM in response to Grant Bennet-Alder

Good question. This unacknowledged disconnection is (sometimes) happening when I unplug the USBC-to-HDMI cable from the Mac (leaving the HDMI-end of the cable plugged into the monitor).

So the cable is being unplugged from the Mac itself.

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Answer 2

xser Author

Level 1

87 points

May 27, 2020 7:36 AM in response to Grant Bennet-Alder

Hi Grant. I am using extended desktop as instructed by Apple.

Turning off "Displays have separate Spaces" produced some unwanted outcomes.

I could no longer use two apps in one split screen space.
The spaces for all my apps were appearing on both displays.

I want my external display to be a separate display above my Macbook's display, and with separate spaces (see arrangement in first post).

The problematic behavior (unacknowledged disconnection of the monitor when unplugging the USBC cable from the MacBook) is happening only sometimes. I will document the conditions under which it happens to see if I can determine cause(s).

Thanks for your help. Other suggestions are welcome.

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Answer 3

May 26, 2020 12:20 PM in response to xser

You look like you want to be using "Extended desktop".

Have you turned off "display have separate spaces", here:

.

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Answer 4

May 26, 2020 8:44 PM in response to Grant Bennet-Alder

Thank you Grant! This was the solution for me, and I'm guessing this is the problem for all other "ghost monitor" issues that are out the on the web. So useful, I even logged in to write this. Thanks!

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Answer 5

May 27, 2020 8:16 AM in response to xser

When all displays are all one "extended desktop" the disconnection of one display force its open windows onto the nearest adjacent display-edge, to avoid them being "lost" and inaccessible from any display. The cursor can no longer move onto the "missing" display.

In contrast, "displays have separate spaces" allows you to access another 'space' (where its open windows are still accessible).

If you want the benefit of "displays have separate spaces", you may have to live with having a display-disappearance NOT causing any changes, and access its windows by swapping its 'space' onto a different display.

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Answer 6

xser Author

Level 1

87 points

May 27, 2020 8:39 AM in response to Grant Bennet-Alder

I'm not sure how to swap invisible windows into a different display—e.g., when the display is disconnect, but the MAcbook is still behaving as if the display is connected and, therefore, putting those windows off its native display.

Is there a shortcut to move all windows to the native display?

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