Big Sur 11.1 External Display Issues!

Big Sur 11.2.3 is installed and I have a brand new MacBook Pro (13-inch, 2020, Four Thunderbolt 3 ports)

Since the software updated, my external USB-C type monitor does not get recognized properly as an external display. It creates the same amount of desktop windows that are on my laptop and when I use the swipe functions on my mouse, the monitor moves screens as well, which is is not supposed to do and was not doing before this upgrade. Please fix!

I just spent $300 on this monitor. It's a Desklab. Thank you.

I've an iMac 27-inch (2017) and a Dell UltraSharp U2715H. Since I've updated the computer to Big Sur 11.2.3 I'm having problems with my external display.

It seems that it works correctly if the Display is on before the iMac is starting. If the display is off when the computer starts, then it will be never recognized although I unplug it or plugin again or even trying to switch off and on the display several times.

I need to restart the iMac with the Dell display connected and switched on to get it working properly again.

I'm having the same problem, Big Sur does not recognize my LG 4K monitor through USB-C - which is the only port on the latest MAcBook Pros!

If I have the monitor on and re-start the computer I can get it part of the way there - it recognizes up to 3360X1890, but that's not 4K, and fine details render incorrectly. This is a major fail for MAC OS, I can't believe this problem has been around since December 2020 and still no fix?

My impression is these are complicated issues on the handshake between the Mac and the display plus development work from the display manufacturer--with Big Sur I have never had a problem with the USB-C to HDMI though I cannot get my Mac Mini 2018 port to work. I have tried every available Big Sur version out and don't think a fix is in the works for the near term.

"it is CLEARLY a software issue, as on MacBooks that have the display issues with Big Sur, the display is recognised and works perfectly with bootcamp or Virtual Machines. If you downgrade to a previous OS the display works perfectly."--but given the integration of hardware and software engineering in a PC this may not be a simple issue for Mac to solve--they may not be able to cleanly provide updated drivers on top of the new OS or easily provide a patch to solve these issues (or they would have done that). As you note one solution might be to downgrade and go backwards to an earlier OS. Although I can't use my Mac Mini 2018 HDMI port w/Big Sur for now it's advantages (and stability) are enough to keep for me.

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.

Valid points, but the displays worked as designed etc PRIOR to a minor .1 update. So someone stuffed up there. And it is quite easy for Apple to roll back to the last batch of drivers and functionality that did, in fact work. It’s not like we are asking them to go back to OS10 ,

And yet, forums just like this are the reason Apple reversed changes to Apple Music, iOS 10.14 updates that broke connectivity over wifi etc etc.

they do actually monitor these forums. If clear and consistent information is posted, then they understand it’s an issue many many people are having.

I hope you are correct. Although it seems a fools errand I keep posting and complaining to Apple directly because it is maddening not to be able to use my external monitor. Certainly Apple is aware of the problem. It seems if Apple wanted to they would have fixed this problem long ago and inexplicably just don't care -- after we have all spend thousands of dollars to purchase their equipment. What to do??? I won't be spending another dime on any Apple product unless and until this issue is resolved.

My impression was my HDMI port failed in the initial upgrade from Catalina to Big Sur--it is possible I first upgraded to .1 but I couldn't be certain one way or the other. However my problem is not the same problem people are facing who can't get their USB-C to HDMI converters to work--and mine always have.

I have a Mac Mini 2018 -- through a series of Big Sur updates the HDMI port will not recognize any external display. Resetting SMC, NVRAM etc. changing cables does not restore the HDMI--the same displays will work with the USB-C to HDMI converter--the Mac Mini 2018 has 4 T3 ports but only 1 for each of the T3 controllers or two total can take a monitor. My LG Ultrafine 23.7" takes one T3 port; I switch off a Samsung 4K nu69000 TV and a LG 27UL600 off of a second T3 port holding the USB-C to HDMI dongle. T3 to HDMI dongles have not worked. I never had a problem with the USB-C to HDMI. Big Sur fixed a display issue I had with Catalina--intermittently Catalina would break the Accessibility > Dislay >Add Contrast controller and go from no contrast to maximum contrast.

Interesting--my other displays were not affected by Accessibility contrast fail--just the LG Ultrafine 4K 23.7" --creating new account off of safe mode w/restarts/reset + reinstall of the Catalina OS eventually stabilized. Then came back but fixed by switching the cable connections for my other two displays (LG 27UL600 and the Samsung nu6900). Big Sur fixed permanently and now has a screen notification when the Increased Contrast is in effect.

And who said I was replying to you. Perhaps you should give Apple pointers on how to run a proper forum while they’re hard at work fixing this issue for us. Weren’t you the guy that asked another why on earth would he use a usb c to usb c connection from laptop to monitor and not hdmi? Lol. You have offered nothing substantial.

Hi, I hope this solution finds you well. I just experienced this issue. I’m sure you’ve found a solution nearly a year later. I found my solution in it being having to purchase Apple’s $39 type c usb cable. Meaning the type c usb cable from my ASUS ZenScreen no longer worked after the update to Big Sur. Despite updating all of the drivers for my ASUS monitor. Prior to the update to Big Sur, my ASUS monitor worked without any issues. Thanks apple. You’re like the printer industry now.

A firmware update to my Dell display seems to have helped in a similar problem with mini M1 Big Sur 11.2.3

DELL M3B106 Fixes & Enhancements 07 Jan 2020

- Adds new OSD option "USB-C Charging" to allow charging over USB-Type-C Port when monitor is powered off

- Fixes no display issue and no charging issue with some non-Dell notebooks or mobile devices