MacBook M1 Pro (2021) + Dell P2720DC - flickering, artifacts?

[benoni]

This has been a second day that this happened. I am running two Dell P2720DC monitors (bought in 2020) plugged via USB-C to my new MacBook Pro M1 Pro (2021) on macOs Monterey 12.1 where only one of monitor starts to flicker and leave "artifacts" on the screen shortly after using my MacBook. This problem with those monitors does not occur when plugged to Lenovo P52 or any other machine.

I checked if that could be the issue with the cable, switched ports, did factory reset on the monitor - I have done literally everything that I possibly could. I thought that the sole fact having those monitors daisy-chained might cause flickering (I have it this setup for other machines) but it is not the case.

Now to the best part of this - once MacBook leaves the "artifacts" and screen flickering EVEN if I unplug the monitor from MacBook, the screen will still show the "artifacts" while both unplugged and plugged to some other machine. Here some sneak peak how it looks like right after plugging the montior to Lenovo machine running Linux:

Note: this background XLSX icon is a leftover from whatever the MacBook was displaying previously on this monitor

Here is the real issue that I am struggling with (it only affects one of those monitors):

1st video (on the left side of the screen the "artifacts" left by the console on the right still remain even after unplugging and plugging the monitor)

2nd video
YouTube link as I can not upload yet another video

This flickering/ghosting/artifacts are visible on this monitor for at least 30 minutes then after random shuffling (plugging/unplugging cables, resetting display settings via monitor menu) monitor starts to work just as new!

I am working on the Lenovo P52 daily for at least 8 hours and it has never affected my monitors so that they would start to flicker like that. Only after switching to MacBook this happens - quick note here that I this just happened recently, I have been using those monitors with MacBook with no issue at all.

Possible conclusions:
1. M1 Pro has issues with my external display (but why only one of them?)
2. My external display has issue with the MacBook
3. Either my monitor or MacBook are faulty

Not sure how should I proceed at this point, I am first timer owner of MacBook.

 

[Internaut]

Are they plugged in via a hub? It might be worth connecting them separately to two of the USB-C ports. I’ve had various issues when connecting via a hub, fixed with a very basic DP to USB-C adaptor and bypassing my Caldigit Soho hub.

Edit: Just proposing a possible workaround; not defending Apple who have, IMHO, been pretty rubbish with external displays in their early Apple Silicon efforts.

 

[benoni]

Are they plugged in via a hub? It might be worth connecting them separately to two of the USB-C ports. I’ve had various issues when connecting via a hub, fixed with a very basic DP to USB-C adaptor and bypassing my Caldigit Soho hub.

Edit: Just proposing a possible workaround; not defending Apple who have, IMHO, been pretty rubbish with external displays in their early Apple Silicon efforts.

They are plugged straight into the MacBook/Lenovo. I am using MacBook Pro M1Pro which has 3 Thunderbolt ports so no need for a hub.

 

[donleon]

following; I have the same display (only 1) and am close to purchasing a new mbp

 

[benoni]

Have been using this setup for quite some time now and what fixed the issue for me was to change the colour profile in the display settings for both monitors from "DELL P2720DC" to "Display P3". I chose the colour profile randomly - picked the one that suited my needs. Why does it fix this issue? I have no idea. @donleon shoutout to you in case you are still deciding

 

[shadow_999]

Have been using this setup for quite some time now and what fixed the issue for me was to change the colour profile in the display settings for both monitors from "DELL P2720DC" to "Display P3". I chose the colour profile randomly - picked the one that suited my needs. Why does it fix this issue? I have no idea. @donleon shoutout to you in case you are still deciding

I had the same issue with one of my dell monitor (the one connected in usb-c, the other is using HDMI). It was connected via a thunderbolt hub (to have a single cable to connect everything and charge the MBP). I was using these monitors with my macpro before without any issue. It happened twice. I had to let the monitor unplugged for a couple of days each time to remove the ghost windows. I changed the profile in the dell from YPbPr to RGB and it didn't occured anymore (I also updated to 12.1 at the same time)

 

[royas]

This is a common issue with the new M1 Macbooks . I think its worth checking out this thread: https://forums.macrumors.com/thread...ckering-with-external-display.2271670/page-12

As far as I understand, there is right now no fix for these issues with external monitors.