Big Sur 11.1 External Display Issues!

You would think they would come up with a hot fix to fix this issue... Make sure to user the "Feedback assistant" app on your Mac to inform Apple about this issue, and point them to this thread. At least that's what I did...

This laggy screen at 30hz is killing me and my productivity, hopefully they'll speed up the fix as they will receive more reports via the Feedback Assistant.

Take care!

Setting to DisplayPort 1.2 on PD2700U causes to only non 4K Res 1080p @60Hz. Changing to 1.1 you at least get all of the res settings except @60Hz. Only @30Hz is available. That Benq only has 1.1 or 1.2 available. 1.4 isn't an option.

Yup, I'm having the same issue. Sounds like this has been an issue since beta. Very frustrating since I'm mostly working off an external display.

The native refresh rate on my display is 60hz but it is now displaying at 30hz. Also when I wake my computer, it doesn't read the display even with the lid open. I have to unplug and replug cable for it to "register."

I've called in and have ongoing conversations with senior techs but no resolution yet.

2019 16" MBP

BenQ PD3220U

Thunderbolt 3

Some quick updates:

• I installed the original 580X graphics card in my Mac Pro Rack under Catalina to see if the problem was with an update to my W5700X card with which I first experienced the issue. Same problem as with the original card.
• if you’re using expensive Owens Corning optical Thunderbolt 3 cables because you needed more than 2 meters of cable length, you are far more screwed than anyone else, i.e. your monitor doesn’t even show up as a display device (no option for reduced refresh rate or resolution).
• Based on the above points, this has to be in firmware within every Mac as changing out the graphics card doesn’t resolve the issue - swallow the Big Sur 11.1 poison pill and you’ll never recover.

Good luck to everyone working through this. I’m pretty frustrated at the lack of testing with configurations applicable to us so called “creative professionals”....

I did it! Totally unuseful! In Italy they just don't know anything about this issue.

They asked me to:

1- disconnect and reconnect the cable

2- try with a usb-c to HDMI cable

3- create a new admin user and try with the new account

...it seems they think we are a bunch of stupids people!

Someone solved by using Display Link. I'm gonna try this today, however it's very annoying to use a third parties driver in order to solve problem with very very basic funcionalities.

Displaylink didn’t work for me. Don’t lose your time. I’ve tried:

switchresx

displaylink

3 times reinstall big sur

and now with a fresh install of catalina don’t work like in the past!!!

or apple solves this or maybe surface, DELL xps ,.... maybe is the solution.

My configuration looks like this. A MAC Mini 2018 and an Apple Thunderbolt Display 27 inch, which is connected with a Tunderbolt 3 to 2 adapter. After the update from MAC OS Catalina to Big Sur 11.01, neither the display audio nor the camera and the USB outputs on the monitor work. The brightness of the display can no longer be regulated. The display starts to flicker even after a short working time. Dan only helps pull out the Thunderbolt plug. Resetting the NVRAM, PRAM, and SMC unfortunately does not bring any improvement. Neither does the update to Big Sur 11.1 or Beta 11.2.

I called Apple and spoke with 3 technicians now. I've been told they are "aware" of the issue but won't confirm or deny that there's a fix in the works. So I hope people keep calling in and reporting the bug.

They made me go through all the troubleshooting steps multiple times now.

I'm running the external display along with a XP-Pen Innovator 16. Same thing. I can make the display work 4k@60Hz sometimes, but no way with the XP-Pen plugged in as well.

It looks like Apple implemented in the OS for all models the restrictions they have on M1 silicon. Something like "Hey, M1 silicon can't run properly two ext displays, so let's do that on MBP16 too!" :(

I have a LG 43" also and without doing any research (thinking I would be able to plug and play and not have to troubleshoot) and I spent 2 days searching for a solution. The lower resolution and bad picture quality was driving me insane! I almost boxed up the monitor thinking that was the main issue. (I did try swapping cables and ports, restart computer etc.) I found your solution eventually, but it's good to know that at one point everything worked fine prior to 11.1 and that it's an OS issue. I hope it gets fixed soon also, would like to get the HDR back and have it set on 1.4 @ 60Hz.

I also have external monitor problems with Macbook Pro 16 2019, MacOS BigSur 11.1 and a LG 34WN80C (ultrawide 4k HDR10).

• The Usb-c to Usb-c connection only has a refresh rate of 30 with the native resolution, I can't choose another option because the option bar is greyed out.
• With a Usb-c to HDMI connection I can choose a refresh rate of 60 with the native resolution. But HDR is disabled; there is no option to enable HDR. This is enabled on the usb-c connection but that is with 30 FPS.

The nature of this bug is that sometimes external displays work but the majority of the time they don’t. I’ve seen many people post success and then come back and say it was a false alarm. I’ve gotten my hopes up a few times in my own experience.

I have exactly the same issues. I have an MB Air M1 and brand new MSI PS341WU. I have to connect directly from the Monitor's USB-C connection to the MB. Tried all the resets possible, no change. I also tried the Caldigit SOHO Dock via HDMI and DP - that made it worse as no connection was being picked up by the MB. Then I tried the Caldigit TS3 Dock and that was fine until the MB went to sleep and on awake the monitor is not recognised. This is just terrible Apple. We are down to one extra monitor for the new MBs (M1) and when the MB goes to sleep, the second monitor is not recognised on the awake. I seem to be going backwards with M1 and Apple.

Today I initialized my MBP16 HDD and made a clean Big Sur Installation.

After that, when I connected my BENQ PD2720u it was well recognized and worked fine. I rebooted and everything was still in place.

I connected then my XP-PEN Innovator 16 1080p. Everything continued to function.

I then tried to turn MBP off and on again...at first the BENQ was black. I switched it off and on an it was back but...guess what...at 30Hz!!! And the display arrangement was also cleared and I had to redo it again.

I just did it old school - I zip up my Music, Downloads etc and do a clean install, which gives me a clean Library folder. I downloaded Catalina installer on an old Mac mini, created a usb stick, used disk utility to delete/create partitions and re-install. My Documents and Pictures folders are in iCloud so that part is easy. I use Firefox which restores browser bookmarks and plugins.