External Displays Swapping - Arrangement Not Remembered!

[Pandybelly]

I just purchased a Mac Studio M1 Ultra and I have two BenQ SW270C monitors hooked up via USB C. This issue has started with the M1 machine. Prior to that I had a Mac Pro 2009 model that used the BenQ monitors, no issues. Previously I had two HP monitors on the MacPro without issue.
I have tried swapping the cables to different ports etc and it makes no difference. When the machine wakes, the screens are swapped.
I tried to calibrate the today with the Palette Software from BenQ and an i1 Pro, no luck either. Kept getting an error message that I needed to plug in a USB cable. I did that and no good.
The screen swapping is a pain.

 

[macsplusmacs]

The screen swapping is a pain.

Agreed.

And worse for my case is that putting my MacBook to sleep only to wake it with windows that were on various screens moved to random areas and screens are killing me a little more each day.

Although I do hope it is related to the Cal Digit dock I am using to drive everything. Hoping to see a fix in the next .1 macOS update.

 

[PianoPro]

I just purchased a Mac Studio M1 Ultra and I have two BenQ SW270C monitors hooked up via USB C. This issue has started with the M1 machine. Prior to that I had a Mac Pro 2009 model that used the BenQ monitors, no issues. Previously I had two HP monitors on the MacPro without issue.
I have tried swapping the cables to different ports etc and it makes no difference. When the machine wakes, the screens are swapped.
I tried to calibrate the today with the Palette Software from BenQ and an i1 Pro, no luck either. Kept getting an error message that I needed to plug in a USB cable. I did that and no good.
The screen swapping is a pain.

I presume you were not using Monterey on the Mac Pro (would have required Open Core)?

Did you try using HDMI on one monitor AND (USB-C or DisplayPort) on the other?

You can dump the EDID's with SwitchResX (trial version) to compare if they are being read as the same using the various monitor inputs? The serial numbers should show up in 2 locations in the EDID (one position is optional). I believe the problem exists depending on which positions the EDID's of the monitors put their serial numbers. You could dump them and paste them here for the various monitor inputs.

 

[milan187]

My first Mac ever and this is driving me nuts. Two identical Lenovo monitors with a USB-Dock, They are both using HDMI, but I tried with one using HDMI and the other DP. Still had the issue. Also tried swapping the two HDMI cables.
Its random.

 

[macsplusmacs]

my issue is not related to the cal digit dock.

MacOS just has a serious problem putting windows in their original places when one has external displays upon wake from sleep.

uggg.

 

[Pandybelly]

I presume you were not using Monterey on the Mac Pro (would have required Open Core)?

Did you try using HDMI on one monitor AND (USB-C or DisplayPort) on the other?

You can dump the EDID's with SwitchResX (trial version) to compare if they are being read as the same using the various monitor inputs? The serial numbers should show up in 2 locations in the EDID (one position is optional). I believe the problem exists depending on which positions the EDID's of the monitors put their serial numbers. You could dump them and paste them here for the various monitor inputs.

Hi,
I was not using Monterey on the Mac Pro.
I cant try HDMI with the studio as it has USB-C only and I don't have an adapter.
I attach the files you requested. They are meaningless to me 😆

My main monitor is on the left-hand side where I keep the dock and menu bar. when I start the Studio or wake it from sleep, the dock and menu bar are swapped to the right-hand screen. I rearrange the monitors and the menu bar in system preferences and it will be changed back again the next time.
Also, the desktop background defaults to the Monterey default at all times. I have set a photo of my own as the default background but it will only appear if I add a new desktop. On a very rare occasion, the Studio has started using my photo as a desktop.
This is very frustrating.

Thanks for helping.....

 

[PianoPro]

Hi,
I was not using Monterey on the Mac Pro.
I cant try HDMI with the studio as it has USB-C only and I don't have an adapter.
I attach the files you requested. They are meaningless to me 😆

My main monitor is on the left-hand side where I keep the dock and menu bar. when I start the Studio or wake it from sleep, the dock and menu bar are swapped to the right-hand screen. I rearrange the monitors and the menu bar in system preferences and it will be changed back again the next time.
Also, the desktop background defaults to the Monterey default at all times. I have set a photo of my own as the default background but it will only appear if I add a new desktop. On a very rare occasion, the Studio has started using my photo as a desktop.
This is very frustrating.

Thanks for helping.....

You can see that the EDID of BOTH monitors is being read as the same Serial Number even though they are different monitors and really have different serial numbers.

BenQ SW270C_1.txt
Descriptor #1 - Serial number:
ETL6M00349SL0

BenQ SW270C_2.txt
Descriptor #1 - Serial number:
ETL6M00349SL0

That is what I have seen before when the problem occurs with otherwise identical monitors. This bug is apparently the reason that the Mac OS can not distinguish between the unique monitors when assigning them to locations and so they come up randomly assigned.

If your monitors had both a DVI and an HDMI input you could solve the problem by connecting one monitor with DVI and the other with HDMI, in which case the DVI EDID will have a different size than the HDMI EDID and the bug will definitely not come into play. But I don't think connecting one monitor with its HDMI input and the other with its DisplayPort or USB-C input will get around the bug and fix the problem. However you should try it if you have the correct cables, since it's a free try.

I've discussed the problem with Apple recently (the problem is not new, I originally had it in my 2010 Mac Pro and it has now reappeared), and it's inexplicable they haven't fixed it. I have no idea if or when they will fix it.

I don't believe over-riding the EDID in the Mac will be effective (because it probably can't keep straight which monitor is being over-ridden) but I haven't tried it. I don't know if that can still be done with the M1 chips (could be with Intel Macs), but if it can I'd try it since it would be free.

What should work would be an EDID emulator that sits between the Mac and the monitor (but I haven't needed to try that approach). You could try one of the cheap ones that could be returned with sufficient fixed features for your application (resolutions, HDCP support, etc), or a more expensive model that allowed you to copy the EDID from different monitor, or program custom changes (changes insignificant to your own usage).

Here's an example EDID emulator (I haven't tried one):

gofanco Prophecy 4K EDID Tester – 17 EDID Modes, Programmable EDID Copier & Manager, Amplifies & Equalizes Signal (4K @60Hz 4;4;4, HDR, HDMI 2.0a, HDCP 2.2, 18Gbps, CEC Pass-Through), TAA Compliant

www.amazon.com

Sorry, that's all I got.

 

[Pandybelly]

You can see that the EDID of BOTH monitors is being read as the same Serial Number even though they are different monitors and really have different serial numbers.

BenQ SW270C_1.txt
Descriptor #1 - Serial number:
ETL6M00349SL0

BenQ SW270C_2.txt
Descriptor #1 - Serial number:
ETL6M00349SL0

That is what I have seen before when the problem occurs with otherwise identical monitors. This bug is apparently the reason that the Mac OS can not distinguish between the unique monitors when assigning them to locations and so they come up randomly assigned.

If your monitors had both a DVI and an HDMI input you could solve the problem by connecting one monitor with DVI and the other with HDMI, in which case the DVI EDID will have a different size than the HDMI EDID and the bug will definitely not come into play. But I don't think connecting one monitor with its HDMI input and the other with its DisplayPort or USB-C input will get around the bug and fix the problem. However you should try it if you have the correct cables, since it's a free try.

I've discussed the problem with Apple recently (the problem is not new, I originally had it in my 2010 Mac Pro and it has now reappeared), and it's inexplicable they haven't fixed it. I have no idea if or when they will fix it.

I don't believe over-riding the EDID in the Mac will be effective (because it probably can't keep straight which monitor is being over-ridden) but I haven't tried it. I don't know if that can still be done with the M1 chips (could be with Intel Macs), but if it can I'd try it since it would be free.

What should work would be an EDID emulator that sits between the Mac and the monitor (but I haven't needed to try that approach). You could try one of the cheap ones that could be returned with sufficient fixed features for your application (resolutions, HDCP support, etc), or a more expensive model that allowed you to copy the EDID from different monitor, or program custom changes (changes insignificant to your own usage).

Here's an example EDID emulator (I haven't tried one):

gofanco Prophecy 4K EDID Tester – 17 EDID Modes, Programmable EDID Copier & Manager, Amplifies & Equalizes Signal (4K @60Hz 4;4;4, HDR, HDMI 2.0a, HDCP 2.2, 18Gbps, CEC Pass-Through), TAA Compliant

www.amazon.com

Sorry, that's all I got.

Thanks for the detailed reply and for going to all that trouble. I have finally calibrated the monitors by unplugging the USB-C from one and calibrating the other with BenQ Palette Master software. Then repeat the process with the other. Of course, what happens now when the Studio resumes from sleep is the calibrations have to be assigned to each monitor again. It's awfully annoying.

 

[jav6454]

my issue is not related to the cal digit dock.

MacOS just has a serious problem putting windows in their original places when one has external displays upon wake from sleep.

uggg.

Does it mix it up?

 

[macsplusmacs]

The displays usually stay in the same place. Its the app windows that might be on screen 1 before sleep that end up on screen 3. times this by three screens and dozens of windows I have open all the time and you can see how frustrating it can be.

I am currently testing out using only 1 LG 5K display. MacBook in clamshell mode. I do lose the extra screens but at least when I wake from sleep everything is in the same place. I am holding out for WWDC. if they ship a 7K I might just get that down the road and stick with one screen.

Mission Control on one screen helps a lot.

 

[Dbrink329]

I may have solved the issue for display swapping on multiple monitors!

My M1 Max 16" MBP currently runs in clamshell and goes to triple 4K monitors. The center has unique specs but the left and right sides are both identical LG 27". They only run 4K 60hz when using Displayport (so HDMI on one is not an option). The theory most people in the forum have is that since they are identical monitors MacOS "forgets" the arrangement randomly when waking from sleep or rebooting, resulting in "swapping".

SOLUTION: I've tried everything in the forum but my latest idea is to use a Startech USB 3.0-to-Displayport adapter with DisplayLINK technology, which might provide it with an emulated profile, thus making it not identical to the other monitor. It has its own graphics card inside and requires a quick software driver installation. So far it is working and I will report back in a few days to see if this holds up! I do get full 4K 60hz using the adapter no problem.

I got it here on Amazon:

StarTech.com USB 3.0 to Dual DisplayPort Adapter 4K 60Hz, DisplayLink Certified, Video Converter with External Graphics Card - Mac & PC (USB32DP24K60), Black

Now you can connect two 4K HDTVs (large format display), monitors or projectors to your Windows or Mac computer, even if your laptop or desktop video card doesn't natively support 4K output. The USB 3.0 (male) to dual DisplayPort (female) monitor adapter lets you extend or mirror your primary dis...

www.amazon.com

 

[Dazamcc]

I just go an M1 Ultra with two studio displays and had this issue when I woke the computer this morning. I might return the whole thing if the issue continues.

 

[fooyork]

I just go an M1 Ultra with two studio displays and had this issue when I woke the computer this morning. I might return the whole thing if the issue continues.

If this is happening with Apple's own hardware then there will almost certainly be an eventual fix. Please, please make sure you speak to Apple Support about this so they can raise it!

 

[Dazamcc]

If this is happening with Apple's own hardware then there will almost certainly be an eventual fix. Please, please make sure you speak to Apple Support about this so they can raise it!

I'm just off the phone with Apple support, they are aware of the issue and say it's being worked on right now. She also gave me a terminal command to reset permissions and said that had worked for a lot of people but not all.

diskutil resetUserPermissions / `id -u`

 

[macsplusmacs]

I'm just off the phone with Apple support, they are aware of the issue and say it's being worked on right now. She also gave me a terminal command to reset permissions and said that had worked for a lot of people but not all.

diskutil resetUserPermissions / `id -u`

These permissions are for the "wake from sleep" windows not being put back on the original displays? And generally showing up on random screens?

 

[Pandybelly]

If I purchase a USB-C to Display port adapter, and fit it to one screen, could it solve the problem?
The other pain, is why won't the desktop background stay on the image I select? It defaults to the Monterey background, yet when I create a new desktop, it uses my preferred image.

 

[Pandybelly]

DISPLAYS NOT WORKING NOW!
I started the studio this morning and neither monitor worked. Checked the monitor menus and they are not receiving a signal. I tried all 6 ports and no good.
I contacted support and despite all suggestions, no minitors.
I kept rebooting and then the recovery screen appeared and I reinstalled OS X as per suggestion on screen. One monitor worked intermittently and then stopped again.
I connected via hdmi and the monitor works. The other monitor connected via usb-c does not display. However, in system preferences>Display, the usb-c monitor is shown as being available.
This is a disaster as I have a wedding to shoot on Thursday and won’t have a mac.

 

[macsplusmacs]

Zap your PRAM?

Is that a thing with the newer M1 macs still?

 

[Pandybelly]

Zap your PRAM?

Is that a thing with the newer M1 macs still?

Tech support said those options didn’t apply to M1.

 

[Pandybelly]

I just go an M1 Ultra with two studio displays and had this issue when I woke the computer this morning. I might return the whole thing if the issue continues.

Hi
Has your issue been resolved yet?

 

[TBD072]

Monitors also swapping positions on new MacBook Pro 14" M1 Pro - using 2 x 24" HP monitors (identical but diff serial numbers). Has now been occuring since Macbook purchased. Both connected via UCB-C.

Never experienced on prior Intel MacBook Pro which I still have.

Has a firm solution every been found?

 

[Pandybelly]

I dropped my Studio to an authorised repair shop yesterday after getting a referral from Apple support.
The technician was unaware of this issue and has suggested, if it’s possible, to roll back the OS to Big Sur and see if that will work.
I have ordered two USB-C to display port cables as a backup option in case he can’t roll back the OS. I have no idea if the cables will work but I’m desperate at this stage.
I have a wedding to shoot on Thursday, more work next week and no computer.
This needs to be addressed quickly as the Studio and M1 is supposed to be the machine for photography and videography.

 

[MissMindeeMayhem]

Along with the monitor swapping, has anyone experienced one of the monitors presenting as having a low opacity "mask" over the whole thing? In addition to the monitors swapping on each other and this desaturated issue, the settings of the displays set to a 40-60Hz range vs. staying at the 60Hz I set it at. The screen looks desaturated until I go in and reset my display settings to 60Hz and HDR. I'm running to identical Benq PD2700U's on a MBP 16" 2021 (M1Max)

My husband is running two identical Dell Monitors (I don't have the model off hand right now) on a MacBook Pro 16" 2019; he has not had this issue at all. I have not had this issue with past MacBook Pros or Mac Pros.....

I appreciate everyone's insight and assistance in getting a workaround for this issue!

 

[SiliconSoldier]

I've had this same issue on a 16" 2019 MacBook Pro with 2 HP V28 4K screens. With, and without a KVM between.

Same story with a 2020 Intel iMac Mini and 2 HP EliteDisplay E221 screens.

Something I've noticed (at least in my case) is that the serial number of the screens is visible in System Information (which you'd think MacOS would use to improve identification...), in theory this information could be used to create a workaround that corrects the display placement.

 

[Dbrink329]

I may have solved the issue for display swapping on multiple monitors!

My M1 Max 16" MBP currently runs in clamshell and goes to triple 4K monitors. The center has unique specs but the left and right sides are both identical LG 27". They only run 4K 60hz when using Displayport (so HDMI on one is not an option). The theory most people in the forum have is that since they are identical monitors MacOS "forgets" the arrangement randomly when waking from sleep or rebooting, resulting in "swapping".

SOLUTION: I've tried everything in the forum but my latest idea is to use a Startech USB 3.0-to-Displayport adapter with DisplayLINK technology, which might provide it with an emulated profile, thus making it not identical to the other monitor. It has its own graphics card inside and requires a quick software driver installation. So far it is working and I will report back in a few days to see if this holds up! I do get full 4K 60hz using the adapter no problem.

I got it here on Amazon:

StarTech.com USB 3.0 to Dual DisplayPort Adapter 4K 60Hz, DisplayLink Certified, Video Converter with External Graphics Card - Mac & PC (USB32DP24K60), Black

Now you can connect two 4K HDTVs (large format display), monitors or projectors to your Windows or Mac computer, even if your laptop or desktop video card doesn't natively support 4K output. The USB 3.0 (male) to dual DisplayPort (female) monitor adapter lets you extend or mirror your primary dis...

www.amazon.com

It has been one full week using the display-link adapter and I can confirm this has worked 100% each time with no exceptions! My monitors no longer swap when waking from sleep or after restart. This solution will work for M1 Pro/Max devices.