How to stop windows moving on external monitors when MBP with M1 goes to sleep?
How does one stop windows moving/switching external monitors when MBP with M1 goes to sleep? This did not happen on my prior 2016 MBP.
MacBook Pro 16″, macOS 12.6
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Jeff_888
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Community Specialist
Hi rrwhitney,
Thank you for participating in the Apple Support Communities. We understand your windows are moving around on your external displays when your Mac goes to sleep. This article can help with making sure everything is set up properly: Use one or more external displays with your Mac
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Set up the displays as an extended desktop
You can arrange your displays in any configuration to create an extended desktop. For example, you can set your external display side by side with your Mac to create one large continuous desktop.
Note: You must be connected to a display to see these options.
- On your Mac, choose Apple menu
> System Settings, then click Displays 
in the sidebar. (You may need to scroll down.) - Click the name of your display on the right, click the “Use as” pop-up menu, then choose “Extended display” or Stop Mirroring.
Set up the displays for video mirroring
Video mirroring shows the entire desktop on each display.
Note: You must be connected to a display to see these options.
- On your Mac, choose Apple menu > System Settings, then click Displays in the sidebar.
- Click the name of your display on the right, click the “Use as” pop-up menu, then choose Mirror for Display.
Set up some displays for mirroring and others for an extended desktop
If more than two displays are connected to your Mac, you can specify that some displays use mirroring (showing the entire desktop) and other displays show the extended desktop (displaying the desktop across two or more displays). For example, if you have three displays, you can have two displays showing the same information and the third display showing the extended desktop.
- Set up all the displays as an extended desktop.
- Press and hold the Option key and drag one display icon onto another display icon to mirror those two displays.
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If everything is set up how you'd like, then you may want to test to see if the issue occurs in safe mode. This can help isolate the issue. Here's how if needed: Start up your Mac in safe mode
If you need further assistance, you may consider contacting Apple Support. Contact Apple Support
Take care.