MacBook Pro M1 external screen flickering

[adao]

I ran into this issue this morning setting up my new work laptop, 16 inch M1 MBPro. I have two Samsung S32D850 Monitors. The flickering happened on one and not the other. I tried switching out all the components from HDMI cables to USB-C adapters to my Macbook Air and concluded that the issue was the monitor itself. So I swapped it with my co-worker's monitor, same make and model(S32D850), and it's working fine. Note that it the monitor was working fine when I was using my Macbook Air.

 

[croco_dile]

I recently bought a Dell U4021QW, and within a week, I have noticed on two separate occasions that the monitor was flickering. And it was driving me insane as the problem would disappear the next day, making it difficult to seek warranty support.

I think I have just figured out the setting that is triggering it.

First, my setup
1. 14" M1 Pro Macbook Pro, running MacOS 12.2.1
2. Dell U4021QW, running latest firmware M2T104, with factory setting
3. The MacBook is connected to the Dell using a Thunderbolt 4 cable. And I have tried different cables.

The flickering would occur when the following conditions are met, and is consistently reproducible:
1. After sunset and before sunrise
2. The Macbook is operating in clamshell mode (ie lid is closed)
3. Night Shift is enabled on the Dell (Schedule: Sunset to Sunrise, Manual: selected), and the Colour Temperature is set to somewhere around the 25% mark (I think this will differ depending on your environment, your monitor model etc)

I can stop the flickering instantly and consistently by doing any one of the following:
1. Manually adjust the Colour Temperature setting either to the left (less warm) or to the right (more warm)
2. Turn off Night Shift altogether (Unselect the Manual tick box, or set Schedule to Off)
3. Flip open the lid of the Macbook screen (ie disable clamshell mode)

Can those of you who are also suffering from similar problems to try this and confirm my theory?

 

[chemistslime]

DELETE

 

[chemistslime]

I recently bought a Dell U4021QW, and within a week, I have noticed on two separate occasions that the monitor was flickering. And it was driving me insane as the problem would disappear the next day, making it difficult to seek warranty support.

I think I have just figured out the setting that is triggering it.

First, my setup
1. 14" M1 Pro Macbook Pro, running MacOS 12.2.1
2. Dell U4021QW, running latest firmware M2T104, with factory reset setting
3. The MacBook is connected to the Dell using a Thunderbolt 4 cable. And I have tried different cables.

The flickering would occur when the following conditions are met, and is consistently reproducible:
1. After sunset and before sunrise
2. The Macbook is operating in clamshell mode (ie lid is closed)
3. Night Shift is enabled on the Dell (Schedule: Sunset to Sunrise, Manual: selected), and the Colour Temperature is set to somewhere around the 25% mark (I think this will differ depending on your environment, your monitor model etc)

I can stop the flickering instantly and consistently by doing any one of the following:
1. Manually adjust the Colour Temperature setting either to the left (less warm) or to the right (more warm)
2. Turn off Night Shift altogether (Unselect the Manual tick box, or set Schedule to Off)
3. Flip open the lid of the Macbook screen (ie disable clamshell mode)

Can those of you who are also suffering from similar problems to try this and confirm my theory?

I have the exact same setup as you do and actually bought another Dell U4021QW to see if the first one I had was a defective unit - I bought it right when it first came out and at that time had a 13" Intel MacBook Pro which does not seem to have this issue. Turns out the second U4021QW has the exact same issue and it might seem to be related to Night Shift but I can't quite confirm it yet. I updated the firmware today to M2T104 from 102, and although it mentions "Fix M1 issue" in the release notes, it does not seem to address my issue. I can still feel a slight flickering but it does seem to be better than it was before. Sigh... I wondering if the LG 40" has the same issue as I'm thinking of switching over to that one. It's such a shame as I really do love this monitor.

 

[croco_dile]

I have the exact same setup as you do and actually bought another Dell U4021QW to see if the first one I had was a defective unit - I bought it right when it first came out and at that time had a 13" Intel MacBook Pro which does not seem to have this issue. Turns out the second U4021QW has the exact same issue and it might seem to be related to Night Shift but I can't quite confirm it yet. I updated the firmware today to M2T104 from 102, and although it mentions "Fix M1 issue" in the release notes, it does not seem to address my issue. I can still feel a slight flickering but it does seem to be better than it was before. Sigh... I wondering if the LG 40" has the same issue as I'm thinking of switching over to that one. It's such a shame as I really do love this monitor.

Have you tried the methods I mentioned?

 

[chemistslime]

Have you tried the methods I mentioned?

I did but it was not reproducible for me. For my monitor, it seems to happen after a period of use and not something that I can pinpoint at this time. For example, when this occurs, when I unplug and replug the cable to the monitor it would stop and other times it would not. Disabling clamshell mode did not help me either, I always have the laptop monitor open as a secondary screen. And as of this writing, I don't have this issue so it seems that leaving the computer unplugged from the monitor and then coming back to it after a few hours helps. It's very strange.

I'm on a 14" M1 Max, 12.3.

 

[croco_dile]

I did but it was not reproducible for me. For my monitor, it seems to happen after a period of use and not something that I can pinpoint at this time. For example, when this occurs, when I unplug and replug the cable to the monitor it would stop and other times it would not. Disabling clamshell mode did not help me either, I always have the laptop monitor open as a secondary screen. And as of this writing, I don't have this issue so it seems that leaving the computer unplugged from the monitor and then coming back to it after a few hours helps. It's very strange.

I'm on a 14" M1 Max, 12.3.

That's interesting, that we are running identical software (I upgraded to MacOS 12.3 today) and hardware (except yours is M1 Max whereas mine is M1 Pro) but are experiencing different problems.

I was almost certain based on my observation that there is an incompatibility between external 3rd party display and Apple's Night Shift mode.

When I have the flickering issue, changing the cables, restarting the monitor, restarting the mac, do not make any difference.

I have uploaded a video to demonstrate my symptoms. It's not very clear, but at around the 6 seconds mark, the flickering starts, and is easiest to see in the white background of my Outlook window, and then as I slide the temperature setting further the flickering stops.

 

[chemistslime]

That's interesting, that we are running identical software (I upgraded to MacOS 12.3 today) and hardware (except yours is M1 Max whereas mine is M1 Pro) but are experiencing different problems.

I was almost certain based on my observation that there is an incompatibility between external 3rd party display and Apple's Night Shift mode.

When I have the flickering issue, changing the cables, restarting the monitor, restarting the mac, do not make any difference.

I have uploaded a video to demonstrate my symptoms. It's not very clear, but at around the 6 seconds mark, the flickering starts, and is easiest to see in the white background of my Outlook window, and then as I slide the temperature setting further the flickering stops.

Hello, I tried what you did in the video and did not get the issue. Looks to be that the 104 firmware might have addressed my flickering. I'll report back if I find anything else or if this surfaces once more. Did you restart your monitor? I had to do that after the firmware update.

 

[fyun89]

I'm on 2021 16 inch Macbook Pro with M1 Max and seeing this issue as well.
But only on one monitor that is using HDMI + Apple Thunderbolt-HDMI dongle. My other monitor that connects with Thunderbolt-HDMI adapter is not having this issue.

Has anyone found a solution yet? I never used night shift mode so that is out of my scope.

 

[chemistslime]

I was able to reproduce my issue for some reason while visiting a kickstarter campaign. When I move off of it, the flickering stops. Nightshift is not enabled. Anyone else have this issue when visiting this page:

EcoFlow DELTA Pro: The Portable Home Battery

Expandable capacity (3.6-25kWh) | Power almost anything (3.6-7.2kW) | Home battery ecosystem

www.kickstarter.com

 

[ekquis]

I have experienced the same issue on/off since I got my 2021 m1 MBpro earlier this year. My monitor is Lenovo Legion Y-25.

Background:
- My old 2016 MBpro had no issues with the same monitor
- My windows computer has no issues with the same monitor
- I use my mac's screen as the secondary monitor and an external one as the main display
- Still on Monterey 12.1

What I have tried:
- Turned off night shift (no help)
- Turned off true tone (seemed to help a bit)
- Turned off freesync from the screen (no help)
- I have swapped out cables, though I have only used HDMI. (no help)
- Tried out the internal HDMI port and via a USB-C hub. (no help)
- Reboots (sometimes helps)
- Updated the external monitor's firmware

What I have realized:
- The lighter the tones on the screen, the less distortion I get
-> Ghosting and flickering seem to get worse, the darker the screen gets (night modes on different apps and in the system)
- Changing the display settings, like hz and so forth randomly on/off and then back to where they were seem to help.
- I work usually from home, 8 hours or so. The problem can be away for weeks, and then start all of the sudden, without much change between the software I use. So a performance/overheat issue (computer on for 7 hours -> something happens) seems to be ruled out(?)

For example yesterday the flickering started all of the sudden again. Today the flickering doesn't happen BUT while dragging windows, the colors get distorted and video gets laggy/blurry

 

[stevemiller]

knock on wood, the think the ghosting and flickering haven't shown up since moving to 12.3.1.

however I have had issues (my own fault) with trying to use screen brightness control software, which says apple silicon compatible, but whenever I have it running, my screen goes to static at random intervals. sad because having to navigate the godawful monitor button menus to adjust brightness throughout the day isn't a great experience.

 

[ekquis]

As an update, I updated to 12.3.1, at least when moving windows around the externalscreen, I can still see the ghosting.

edit/update2: I turned off "HDR" from the monitors own settings (not via the mac). Seemed to help a bit, again. But this has gone on/off before as well...

 

[itsmesteven]

Been on the phone with BenQ product engineer. They told me that flickering is a known issue with M1 and no fix at the moment as for 5 April 2022. BenQ and Apple is working with solution for this.
Firmware version 021, 022 for PD3220U do not fix anything according to BenQ.

 

[stevemiller]

Been on the phone with BenQ product engineer. They told me that flickering is a known issue with M1 and no fix at the moment as for 5 April 2022. BenQ and Apple is working with solution for this.
Firmware version 021, 022 for PD3220U do not fix anything according to BenQ.

ugh. I really hope they do manage a fix soon.

 

[Ithrial]

So I just received a new MBP M1 Pro from work with an "approved" Dell thunderbolt dock. Was originally going to use a couple of HP LP2475 and a Dell 2007FP - Good solid IPS displays for work stuff - nothing fancy. Also sorts of flickering. Did some research and found a common thread that pretty much every having issues had an IPS (not saying that all IPS were having issue but seemed that all issues were on IPS). So I swapped to an LG 32GK850G-B (VA) and a couple of cheap Spectre 19" (TN) screens - no flickering what so ever. Even had the LG up to 165 on the overclock on the dock and no problems.

Went back thru the thread and other folks that had good results were mostly non-IPS displays. Just putting this out there

 

[ekquis]

So I just received a new MBP M1 Pro from work with an "approved" Dell thunderbolt dock. Was originally going to use a couple of HP LP2475 and a Dell 2007FP - Good solid IPS displays for work stuff - nothing fancy. Also sorts of flickering. Did some research and found a common thread that pretty much every having issues had an IPS (not saying that all IPS were having issue but seemed that all issues were on IPS). So I swapped to an LG 32GK850G-B (VA) and a couple of cheap Spectre 19" (TN) screens - no flickering what so ever. Even had the LG up to 165 on the overclock on the dock and no problems.

Went back thru the thread and other folks that had good results were mostly non-IPS displays. Just putting this out there

This is very plausible, have been trying to figure out what is the reason why it works somewhere and where it doesn't.

My screen at home is an IPS, I have problems there. My screen at work isn't an IPS and it works just fine.

 

[MoFun]

Like everyone here I'm having the same flickering issue on external NON-IPS monitors. I've tried everything recommended and no luck. Today I visited the Apple store and met with a Genius Bar employee. He ran a test on my MacBook and said that all the hardware tested out fine. His only recommendation was to reinstall the OS (Monterey). **** HE ALSO SAID THAT THE MORE PEOPLE THAT REPORT THIS TO APPLE WOULD INCREASE THE CHANCE OF IT BEING ADDRESSED **** PLEASE REPORT THE ISSUE TO APPLE SO WE CAN GET THIS TAKEN CARE OF. Please go here to report it: https://feedbackassistant.apple.com One on the site click on the "Pencil and note" icon towards the top left to post a bug.

 

[kindof665]

ugh. I really hope they do manage a fix soon.

Hey is the issue fixed on your benq monitor? i recently purchased mac studio with m1 max chip and 32 core gpu and along with that i also purchased a benq pd2700u the same monitor as urs and i had also downloaded monitor control when i got my monitor that was on 22nd so after a day i started seeing flickering issues after some research i concluded that it might be the 3rd party software thats causing the issue . i had uninstalled it today but the flcikering still seems to happen from time to time its not constant but it does happen and idk what to do about it so hows your situation currently should i return the monitor ? idk what to do , pls let me know hows the issue is going so far with you

 

[kindof665]

I went ahead and ordered a new Monitor. Looked up, and people seemed to be happy with their UltraFines from LG, so I've ordered the LG 32UN880-B UltraFine. Got a 1 month time period to return the previous Samsung one, so I will send this one back.

I really hope that the new one works fine without flickering ... Otherwise I will be pushed into selling this MacBook & getting a Windows Machine.

any update as to what happened? i just brought a mac studio, i was completely unaware of this whole external monitor flickering issue and i have benqPD2700U 4k monitor and sometimes it flickers idk what triggers it but now reading the whole thread am scared as to what i have gotten myself in again pls let me know the current situation!

 

[kindof665]

Just an update on the LG 32UN880-B UltraFine. Connected it with LG's provided USB-C -> USB-C, and it works great without any flickering. I was actually quite surprised by how well the colors look on it. It only took me to 2 monitors to find the 3rd lucky charm .... Went through hell, but glad LG worked (Dell & Samsung didn't).

I still hope that Apple provides a fix for everyone, so they can use their monitors as its meant to be used.

is it still working fine????

 

[kindof665]

I have noticed a flickering on my external monitor (a BenQ PD2700U) connected to my MBP 14" Pro via USB-C to DisplayPort. Does it now and again then clears. very annoying.

I've actually now switched to an 8k rated HDMI-HDMI cable. I notice that the PD2700U stays at 60hz refresh rate on HDMI, where USB-c to DisplayPort would keep switching back to 40-60hz variable (monitor would show it was running at 40hz). Will see how it goes on HDMI

hey there is the flickering issue still there? i recently bought the same monitor for my newly bought mac studio pls let me know as seeing the whole thread is making me think of returning the damn thing! as it seems to be a problem with m1 chips and not with monitors pls let me know. Thanks!

 

[kindof665]

So, I just had this flickering problem occur today, running my 2020 M1 Macbook Air via Thunderbolt 3 into a brand new BenQ DesignVue PD2725U monitor – which had been working seamlessly for a month or so. Nothing seemed to fix it, until I tried the "disconnect power cable and thunderbolt cables for 10-minutes" thing. Just booted back up, and it works again. For now.

I also turned off night shift. which I had been running nonstop. Figure I'll just go for the eye-care mode of the BenQ monitor instead.

So, thanks hyouuu!

has the issue been fixed for you after disconnecting the power cable for 10 mins or the issue is still going on?

 

[stevemiller]

any update as to what happened? i just brought a mac studio, i was completely unaware of this whole external monitor flickering issue and i have benqPD2700U 4k monitor and sometimes it flickers idk what triggers it but now reading the whole thread am scared as to what i have gotten myself in again pls let me know the current situation!

I'm on macOS 12.3.1, the monitor control app is uninstalled, and while I can't say for sure if things are completely fixed (I feel like there are a few times where I might detect some subtle flickering), it hasn't been too bad the past little while.

Another thing I did was go into the monitor's on screen settings and explicitly turned off DCC/CI in the system category. It apparently doesn't work with HDMI on apple silicon, and could have been a source of the static and flickering? I haven't yet invested in a DisplayPort to usb c cable to see if that connection is any more reliable. Here's a thread of some people discussing the DCC issue:

M1 Mac does not support DDC/CI | Apple Developer Forums

developer.apple.com

 

[kindof665]

I'm on macOS 12.3.1, the monitor control app is uninstalled, and while I can't say for sure if things are completely fixed (I feel like there are a few times where I might detect some subtle flickering), it hasn't been too bad the past little while.

Another thing I did was go into the monitor's on screen settings and explicitly turned off DCC/CI in the system category. It apparently doesn't work with HDMI on apple silicon, and could have been a source of the static and flickering? I haven't yet invested in a DisplayPort to usb c cable to see if that connection is any more reliable. Here's a thread of some people discussing the DCC issue:

M1 Mac does not support DDC/CI | Apple Developer Forums

developer.apple.com

Couple of questions-
1. How long have u had the studio for and has the flcikering worsen or got better with updatws?
2. I talked with one of the ppl on mac forums here only where in he told me he got new mac studio and got a refund for the old one and in his new unit there are no flickering issues, so like is it your first unit or you have also gone through a replacement.(i will link u the thread and he even has the exact same display as mine which is Benq PD2700U 4K)
3. Do you think its a display issue or cable or studio issue like hardware wise or is it something related to software?
4. My only concern is that somehow the flickering shouldnt get worsen overtime coz as of now it may happen for a total of 20 sec at max in the whole day its not very persistent as of now.

so what should i do? should i keep it or get a replacement ? coz i need a computer for my work and i cant go the pc route.

Here is the link for pt 3 - https://forums.macrumors.com/threads/mac-studio-screen-flickering.2338756/post-31048019

Pls let me know. Thanks for the help