How to maintain multiple monitors arrangement between reboots

[PianoPro]

Mac Studio/Monterey has the same old problem of randomly switching around a multiple monitor arrangement between reboots that goes all the way back to my G4 and G5 Power Mac towers, and my 2010 Mac Pro. I have 3 monitors connected to the Studio, two of which are the same HP monitors (I know using 2 of the same monitors triggers the problem). Those 2 randomly come up up switched in position and assigned as the main monitor on reboots. The 3rd monitor (different brand) never changes it's position.

Somehow I fixed this problem (or at least it went away) years ago on my 2010 Mac Pro, but I can't remember what finally stopped it from happening. Now it's back with my new Studio using exactly the same monitors.

Has anyone ever found a reliable fix for this problem?

 

[hg.wells]

I use an app called Stay that will open apps on a specific monitor.

Cordless Dog: Stay

cordlessdog.com

 

[PianoPro]

I use an app called Stay that will open apps on a specific monitor.

Cordless Dog: Stay

cordlessdog.com

Restoring apps to the same monitor is not the problem.

The problem is that the desktop arrangement is swapped from one monitor to another.

 

[hg.wells]

Restoring apps to the same monitor is not the problem.

The problem is that the desktop arrangement is swapped from one monitor to another.

Apologies, didn’t read your message properly.

 

[BanditoB]

I know it is obvious, but i would contact Apple Support and let them solve the issue for you.

 

[PianoPro]

Judging from the lack of responses, presumably no else has had this very old Mac OS/OS X problem appear in their Studios. But since I found the cause I will document it here for archiving purposes in case someone else has it in the future.

I used Migration Assistant to move files from a 2010 Mac Pro running Mojave to the Studio. It moved 2 files from the Mojave OS that shouldn't have been moved at all since they are no longer compatible with the Monterey OS.

/Library/Preferences/com.apple.windowserver.plist
~/Library/Preferences/ByHost/com.apple.windowserver.*.plist

The new Monterey versions are:

/Library/Preferences/com.apple.windowserver.displays.plist
~/Library/Preferences/ByHost/com.apple.windowserver.displays.*.plist

I have no idea why Monterey would even read the files with the older names, but apparently it does. Once I removed them I haven't had the problem once in the last 3 days (I've forced many unnecessary logout/logins, and reboots to test).

 

[BanditoB]

Great find! I’m glad you were able to resolve it.

I guess this is yet another reason why migrating the configuration may cause some unexpected/unanticipated behaviors in the new system.

You should consider providing this information as feedback to Apple at apple.com/feedback. Once aware, they may correct the issue.

 

[Canezmd]

Judging from the lack of responses, presumably no else has had this very old Mac OS/OS X problem appear in their Studios. But since I found the cause I will document it here for archiving purposes in case someone else has it in the future.

I used Migration Assistant to move files from a 2010 Mac Pro running Mojave to the Studio. It moved 2 files from the Mojave OS that shouldn't have been moved at all since they are no longer compatible with the Monterey OS.

/Library/Preferences/com.apple.windowserver.plist
~/Library/Preferences/ByHost/com.apple.windowserver.*.plist

The new Monterey versions are:

/Library/Preferences/com.apple.windowserver.displays.plist
~/Library/Preferences/ByHost/com.apple.windowserver.displays.*.plist

I have no idea why Monterey would even read the files with the older names, but apparently it does. Once I removed them I haven't had the problem once in the last 3 days (I've forced many unnecessary logout/logins, and reboots to test).

Thank you so much for posting this. I have the same problem. Gonna try this fix.

 

[Canezmd]

Judging from the lack of responses, presumably no else has had this very old Mac OS/OS X problem appear in their Studios. But since I found the cause I will document it here for archiving purposes in case someone else has it in the future.

I used Migration Assistant to move files from a 2010 Mac Pro running Mojave to the Studio. It moved 2 files from the Mojave OS that shouldn't have been moved at all since they are no longer compatible with the Monterey OS.

/Library/Preferences/com.apple.windowserver.plist
~/Library/Preferences/ByHost/com.apple.windowserver.*.plist

The new Monterey versions are:

/Library/Preferences/com.apple.windowserver.displays.plist
~/Library/Preferences/ByHost/com.apple.windowserver.displays.*.plist

I have no idea why Monterey would even read the files with the older names, but apparently it does. Once I removed them I haven't had the problem once in the last 3 days (I've forced many unnecessary logout/logins, and reboots to test).

I couldn’t find the “byhost” files… maybe I don’t have one?

 

[PianoPro]

Thank you so much for posting this. I have the same problem. Gonna try this fix.

Sadly, the problem came back a few days later. But someone else posted a fix in another thread that seems to have worked. I had both identical monitors connected to their HDMI inputs and the Mac can't tell them apart by their serial numbers. He suggested using different monitor inputs for each. I switched one monitor to using its DVI input and haven't seen the problem again in a week.

 

[Canezmd]

This is frustrating... It doesn't make any sense why the Mac can't select based on what port it's plugged in to. For instance if you have 2 of the same monitors both using USB C ports, it should be able to pick port 1 as always on the left and port 2 as always on the right in the arrangement. It shouldn't be this difficult for a Mac that's made to work with multiple displays.