Major connection issues with LG UltraFine 5K and Apple MacBook Pro 13 M1 since Big Sur 11.4

[weidenhaus]

Hey friends,

I'm having major display connection issues ever since upgrading to Big Sur 11.4. Here is my config:

- Apple MacBook Pro 2020 M1 13-inch (8CPU / 8GPU)

- LG UltraFine 27inch 5K (latest version, bought in 2020)

- Same effect using the LG included Thunderbolt 3 Cable or the thick 0.5m Apple Thunderbolt 3 cable

- LG Display is the primary display



The issues are, when waking up from sleep:

- The internal & external displays seem to fight who is the primary (Top Menubar keeps appearing on both, wallpapers are flickering). Can't click on anything, keys are working with lag

- The topmenu seems distorted and can't be clicked

- Even when the issue seem to be resolved after plugging the cable in and out a couple of times , sometimes when I click on anything the mouse cursor jumps to the very top of the screen



What I've tried so far:

- Using different Thunderbolt 3 cable

- Replacing Wallpaper with solid color

- killall Dock (does not restart dock - both displays are constantly flickering)



The only thing that works currently is plugging the cable in and out a couple of times (4-6x)



IMPORTANT: On my company provided MacBook Pro 2020 16inch with latests Catalina - no problems whatsoever.

Thank you all!



Here is the console.app output:



```

error 14:37:06.851958+0200 Dock Invalid display 0x00000000

error 14:37:06.901004+0200 Dock +[MTLIOAccelDevice registerDevices]: Zero Metal services found

error 14:37:06.958439+0200 VTDecoderXPCService +[MTLIOAccelDevice registerDevices]: Zero Metal services found

error 14:37:07.263525+0200 Dock display 0 had unexpectedly empty bounds.

error 14:37:07.263545+0200 Dock Pre-mitigation state:

error 14:37:07.263556+0200 Dock main display: 0

error 14:37:07.263566+0200 Dock display 0x1 (0x1, 0x0, 0x0)

error 14:37:07.263575+0200 Dock display 0x2 (0x2, 0x0, 0x0)

error 14:37:07.263581+0200 Dock display 0x3 (0x3, 0x0, 0x0)

error 14:37:07.265556+0200 Dock Post-mitigation state:

error 14:37:07.265636+0200 Dock main display: 0

error 14:37:07.265710+0200 Dock display 0x1 (0x1, 0x0, 0x0)

error 14:37:07.265789+0200 Dock display 0x2 (0x2, 0x0, 0x0)

error 14:37:07.265870+0200 Dock display 0x3 (0x3, 0x0, 0x0)

error 14:37:07.276544+0200 runningboardd Ignoring invalidation request for 357-322-301 because it doesn't exist

error 14:37:07.277019+0200 runningboardd Assertion invalidation request from 322 for identifier 357-322-301 failed

error 14:37:07.729676+0200 symptomsd failed to start ticker tickerFatal, not active, active probe: 0x0

```

 

[borisdivjak]

I’m having the same issues, haven’t had any luck outside of plugging the cable in/out.

Have you been able to resolve this yet?

 

[weidenhaus]

I’m having the same issues, haven’t had any luck outside of plugging the cable in/out.

Have you been able to resolve this yet?

Hi Boris,

I was on the phone with Apple Support yesterday, they told me that they never came across this issue before, but I think I found a solution. In the Display Arrangement Menu in System Prefs drag the white bar on the MacBook Pro to make it the Primary Display and after a few seconds drag it back to the LG. In my case it solved the problem. There is still some flickering sometimes when waking from sleep, but after a few seconds everything is where it should be. I guess by changing the Primary Display some preferences / display IDs are updated in the background.

Have a good week

 

[borisdivjak]

Thanks, interesting workaround. I'll give it a try when I next get the issue.

 

[john123]

+1 on this issue too. Do either of you get serious system slowdowns sometimes when plugging in? This might just be me already being up against the memory limit already.

 

[borisdivjak]

I’m not having issues with a slow system. It’s just the screen that doesn’t always connect properly. Whenever this happens I also get issues with drag&drop functionality (in all apps) as well as screenshots not working properly.

I’ve noticed that it helps if I don’t have too many apps open, though. When it happens now, I just close all my apps and reconnect the screen and then it’s usually fine.

 

[john123]

I’m not having issues with a slow system. It’s just the screen that doesn’t always connect properly. Whenever this happens I also get issues with drag&drop functionality (in all apps) as well as screenshots not working properly.

I’ve noticed that it helps if I don’t have too many apps open, though. When it happens now, I just close all my apps and reconnect the screen and then it’s usually fine.

Interesting. Same thing with fewer apps with me. So I wonder if there is some sort of load component to it — and I’m getting double whammied because of memory pressure too.

 

[borisdivjak]

I just updated my system to Big Sur 11.5.2 and the issue seems to be resolved. 🤞