Big Sur 11.1 External Display Issues!

I've updated this morning from 11.2.1 to 11.2.2, closed all windows, programs, etc and rebooted (with monitor connected via USB-C cable - this is a DELL 27''), but still I have the message that 'no USB-C signal is detected by the monitor'. This is when I use my newer MacBook Pro (13-inch, M1, 2020, 16 GB memory, OS: Big Sur 11.2.2). If I try with my older MacBook 11-inch laptop (running Catalina - I've decided not to update it for now) I have no problem whatsoever to connect the same monitor with the same USB-C cable. I filed a bug report using https://www.apple.com/feedback/macos.html

I confirm that my LG 4K HDR is working on USB-C -> DP cable after upgrade to 11.2.2, but I can't seem to get 60 Hz refresh rate (which I had before 11.1)

HDR option is available in Display Settings, so I guess this is somehow fixed.

I'm on a 2020 16 inch MBP

I had a call from the Apple Support about this bug today. The problem remains unsolved.

I connect an 17" Eizo S1721 with a original Apple DVI to USB C adapter to a 2019 Mac Pro running a newly installed and clean version of Big Sur. The Monitor is not properly recognised, after Big Sur boots up. If I reconnect the S1721 after the boot it works as it should, until It shut down the Mac Pro 7.1 and boot up again. Another Monitor, an Eizo CS2730, is connected via an hdmi to USB C cable. This one works without any problem on both inputs of the standard RX580. The S1721 isn't properly recognised on both inputs.

The Apple support did not have a solution to this problem and suggested, that I try different adapter solutions.

It was also mentioned, that we are possibly just have to wait for an update, that fixes the problem.

I'll be checking different adapter dongles and cables now and will report if I find something that works. I think, the chances are low.

I'd hold off the upgrade, My 2 external monitors were working fine 'till I upgrade to BIG SUR.

I've got:

Apple cinema display 24-inch (1920 × 1200) via mini display port

Connected via a Startech Thunderbolt dock

Viewsonic TD2340 23-inch (1920 × 1080) via HDMI

They do work, but MacBook Pro (15-inch, 2017) slows to a crawl often, especially if I use Zoom....it becomes unusable....and i have to unplug the external screens and just sue my macbook, which is a real pain when i need to manage /share several others tabs in chrome/safari etc....

I’ve noticed with Mac’s activity monitor that the CPU comes under heavy load with KERNEL_Task, WindowServer and Google Chrome Helper (render) usually at the top of the list….

I was wondering if there is an issue with overheating which can slow things down, or maybe the SSD degrading.....but it all points to something in Bir Sur that doesn't like supporting external screens.... as my Macbook is fine when nothing else is plugged in....

Come on APPLE, you've upset an awful lot of people with this....!

I use a MBP 16" (2019, AMD Radeon Pro 5500M, Bug Sur 11.2.3 (20D91)) too with an USB-C connected LG32UD99-w (max resolution 3840x2160, refresh rate 60Hz).

With SwitchResX you can set the resolution to eg 2800 x 1800, or higher, BUT the refresh rate is in my case always at 26.00Hz :-(

--

AMD Radeon Pro 5500M:

  Chipsatz-Modell: AMD Radeon Pro 5500M ...

Displays:

Farb-LCD:

  Displaytyp: Integriertes Retina-LCD-Display

Auflösung: 3072 x 1920 Retina ...

LG HDR 4K:

  Auflösung: 2880 x 1800

  UI sieht aus wie: 2880 x 1800 @ 26.00Hz

  Framepuffertiefe: 30-Bit Farbe (ARGB2101010)

Still no fix from apple, but I guess they really do want us all to go buy new displays. My 20" Cinema displays still flash on and off like a demented disco light if my MacBook Pro 13" 2007 goes to sleep.

BUT

After installing SwitchresX, I now have full control over my resolutions back and I can actually safely and successfully drive the 20" cinema at 4K resolution!

With a MacBook Pro 16" (2019), my BenQ PD2700U on DP 1.1 works at 3840x2160 60p via Hyperdrive hub > HDMI > HDMI, but not USB-C > DisplayPort.

USB-C > DisplayPort gives me full resolution but not full framerate on DP 1.1, and low resolution and low framerate on DP 1.4. HDMI also gives me low resolution and low framerate on DP 1.4.

I have been involved in this Discussion Group almost since day one. Please look at the name of the Discussion Group. This is about External Displays not working on Macs, as they should, since the introduction of Big Sur 11.1. This covers MacBooks, iMacs and Mac Minis. All Mac Models (MBs, iMacs & Mac Minis) are affected in Big Sur whether intel based or M1 based. More importantly, Apple seems to be doing nothing about the issues. This is where we should be focusing our energies.

Welcome to the thread where all the exact info has been posted thousands of times over the past 120 days. Rather than skip to the last page of the thread you should have read the posts before wasting your time with your post. I was selected from this thread by Apple and went through the senior level tech support the beginning of February. I spent hours of my time trying to be over the top helpful to contribute to a solution to this issue. After the info was collected from me Apple went dark. Have not hear back in months. There is nothing more anyone can add to the conversation that will help determine the root causes. It’s simple 11.0 it worked, 11.1 broke it. Compare the code and identify anything related to external monitors and fix it. It’s clear any products containing Intel processors are not a priority to Apple. All we can do is keep increasing the views and post count to keep this thread up at the top of the list.

I contacted support again today, as it's been 6 months with three os updates and still no fix for me on an LG 32UD99 32" 

Display.

The support person I spoke with said the best way to let the macOS engineering team is via feedback using this url:

https://www.apple.com/feedback/macos.html

enter the details, explain the issue and let them know this is still an ongoing problem. I've spend several hundred dollars on work arounds to have some expensive kit rendered obsolete. Might have well just purchased a cheap 1080p monitor for a fraction off the price. This is really not good enough apple!

The Catalina linked to is an update of 10.15.5 not an install of the latest 10.15.7. You may not have success trying to downgrade from Big Sur simply to a 10.15.5 iteration w/Big Sur loaded. It may not be enough to install--it may not be accepted as an installation on a Mac already holding Big Sur. I erased my hard drive before in recovery mode as advised and tried to install prior Catalina OSs from a list off of this link:

How to get old versions of macOS - Apple Support

there the Catalina link takes you Mac Apple Store download of Catalina and I was told by my Mac the installer key was too old for my Mac. I recovered a version of Big Sur instead.

This link may work but I would backup files and data first before I tried.

In case anybody is wondering, this problem has still not been fixed.

I have a 16" Macbook Pro (2019) - I had zero problems before the 11.1 Big Sur update in December 2020. Since then, my Macbook has not been able to use external displays with via Thunderbolt 3 / Displayport.

I have never had any problems with my TB3 <-> HDMI adapter. The problem is - and always has been - with Displayport profiles over TB3. I am very disappointed with Apple - 5 months and still no end in sight.

This is what worked for me:

1. Install the newest version of display link, which can be downloaded here: https://www.displaylink.com/downloads/macos
2. Once installed, go to finder > applications > double-click on Display Link Manager
3. This will open your system preferences > Privacy to authorize display link for Screen Recording
4. Allow permissions
5. All set :)

Still not working for me with a BenQ SW320 and a MBP 16" / 2019. I have tried using Targus and OWC docking, going direct, shifting ports, shifting from DisplayPort 1.1 to 1.4, etc. When Big Sur awakes and doesn't detect the screen the sole solution is to reboot, otherwise anything like unplugging/plugging back the screen either directly or via the docking or docking/undocking just leads to a kernel crash... Honestly I haven't had to restart so often a mac in more than decades.

Also to be noted the Bluetooth is lagging with the TrackPad, I have to use it wired with a lightning cable for it to be usable!

It feels like a bunch of stuff, performance wise are totally screwed with Big Sur but hardly understand how it could the 4th update and such issue not been resolved. Let's hope for Monterey... or the 11.5...

Well, Part 2. Before I gave up and walked away for the day, I thought I'd restart the iMac one more time, after installing the 11.5.2. Lo and behold, when it came up, my Acer monitor was working as the second display and showing up System/Display Preferences! MAYBE it IS fixed...hoping it will hold and stay this way. If so, thanks Apple, really! Took a long time, but thanks for getting it done - assuming this is for sure a fix! Only took 2 hours out of my day... :+O