Windows moving to the wrong screen after waking from sleep

[_keith_]

I have a Mac mini 2018 running Big Sur 11.6.3 connected to two LG displays. The displays turn off after 5 mins of inactivity and sometimes when I wake them back up the windows that were on my second screen have all moved to the first screen, and there are no windows on my second screen at all! This doesn't always happen but when it does it drives me crazy!!

Is this a bug or is there some setting that might control this?

I have un-ticked "Displays have separate Spaces" in System Preferences > Mission Control, but all other settings are using their defaults as far as I can remember.

 

[appltech]

Head over  System Preferences and find there the power section. Pick "Prevent your Mac from automatically sleeping when the display is off" maybe this will helps

 

[excrispy]

I have two, 32 inch 1080p external monitors connected to my mac. I never had a problem until I upgraded to Monterey, and for some reason the windows would be in the wrong places after I wake up the computer.

I found that my USB-c dongles were bottlenecks for the HDMI cables. So one or both monitors were waking up slightly delayed, which would cause the rearrangement of windows. Changing my cables to display port to USB-c cables (so no dongle) fixed my problem immediately, and the desktop windows are all in the right places.

It also depends on what kind of monitor you have. If you have 4k or 120hz monitor, you should try to get an HDMI 2.0+.

Hope that helps.

 

[efrancis76]

I had the same problem with 2 LG screens. It seems that LG is using the same identifier in most of their screens and that MacOS uses that id instead of the serial number to know which screen is which. I exchanged one of the 2 LG screens against a monitor from a different brand, and right away the problem was gone.