Big Sur 11.1 External Display Issues!

I'm having the issues as well and I've been talking with senior techs for the past few days. Sounds like the issue is on their radar but I'm sure it wouldn't hurt for everyone else to also call in as well.

2019 16" MacBook Pro

32" BenQ PD3220U

I have this same issue with my BenQ PD2700U Display:

Before 11.1 Update - all works as expected - Display supports full @60Hz.

After - max @30Hz when doing 4K.

Using the App Display Menu shows that no Retina supports 60Hz anymore.

THIS IS CRAZY!!!! Please FIX this ASAP.

I have a 2019 Mac Pro Rack with an AMD Radeon Pro W5700X module and a 34" LG 34WK95-U "5K2K" ultra-wide monitor using an optical Thunderbolt 3 cable. This combination worked just fine on the last version of Catalina. I'm having what sounds like the same problem:

• I upgraded to Big Sur 11.1 (specifically waited for the first dot release) and could not get the display to be recognized after the upgrade.
• I even downgraded back to Catalina via Time Machine backup and reinstalled the OS. The system works, but it still can't detect the display.
• I can get the display to work if I hook it up to my OWC Thunderbolt 3 dock in between it and the computer, but it won't do 5K resolution.
• I was also able to get it to work if I used Thunderbolt 3 to 2 adapters on both ends using a Thunderbolt 2 optical cable in between, but again it wouldn't do the full 5K resolution.

My thought there was a firmware update included in Big Sur for various display adapters and/or some other component in the driver stack for displays that is messing all this up. This is one of those times I wish I could roll back firmware on an Apple-branded graphics card.....

Overall I too regret pulling the trigger on the Big Sur upgrade. Hope this gets fixed as this has me largely shut down at the moment.

After the latest Big Sur update, we too lost separate control of our monitors (iMac 2020 with Wacom Cintiq Pro 24" tablet). If we leave the iMac in SLEEP mode and the Wacom in its SLEEP mode each night rather than shut down/reboot the next day, then a touch on the SPACE bar brings everything back to life as before. But on a reboot the monitors switch to MIRRORING with the Wacom the predominant monitor available in SYSTEM Preferences and the iMac screen unavailable. The only cure is to turn off the Wacom tablet, then turn it on again to let the OS recognize it as another monitor if we have rebooted or logged out. Also, we have to re-adjust the BRIGHTNESS settings on the iMac monitor because the OS boosts it to MAX on each boot up. We calibrate our monitors with a Spyder Pro and fortunately the OS remembers the Spyder Pro ICC profile! So far this procedure is working for us but we are not hopeful this 'fix' will remain available until Apple repairs this quality control issue.

Please call apple support as i did. Because they do not know. They suggested to do everything you all tried. Only then they can find the bug they say. But i am facing a deadline so i can only do it somewhere in januari. The more people send complains to apple support on this, and best is calling, the sooner it will be fixed they told me. This here is an external site that their technicians - to my astonishment- do not follow!!!!

Post a feedback on the apple feedback form! we need to make them understand how big is the community experiencing this issue! Customer service is not aware of the problem!

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

I have the same problem with a

13 inch 2020 4 Thunderbolt MacBook Pro on

macOS 11.1 Big Sur

connected either via a Thunderbolt dock WD19TB or a Thunderbolt USB-C hub to

a receiver (Denon ARR4520)that in turn is connected to a 1920x1080 monitor (not a tv as it does not have speakers).

The problem is there with the Thunderbolt ports on the left side as well as with the Thunderbolt ports on the right side of the MBP.

By the way: both receiver and monitor do not have ARC, this is simple HDMI.

Shortly the image appears than disappears and image flickers between black and scrambled etc.

Receiver and monitor work and have been working perfectly with Dell Windows10 laptop via the same dock.

Receiver and monitor work perfectly with other devices (Playstation 4, settop box, 2 different HP Windows10 laptops with HDMI-port, Microsoft Surface Pro 3 connected via Surface Dock and minidisplay port to HDMI converter)

This is all via the same Supra HDMI cable.

The MPB connected via the same dock to a (2x1920)x1080 display via a USB-C out works perfect: the MBP sees this as a DisplayPort connection (according to the Midi-settings).

PRAM and SMC reset done: problem remains.

The receiver supports 4K.

The monitor does not support 4K, only 1920x1080.

Connected monitor to the HDMI cable: image stable (no sound as monitor does not have an amplifier nor speakers).

So the problem seems to be the resolution being higher than 1920x1080 via HDMI even if via a dock or hub.

Called Apple support: support didn't accept it to be an Apple problem and referred me to the receiver manufacturer.....

I had this issue with my macbook mini and found the following solution. I found a youtube video that gives step by step instructions. Posting it below with the hope that it may help others. Please let me know if this works for you.

https://www.youtube.com/watch?v=5ZgnEwHxgxo

I spoke with a "senior technical support rep" from Apple Support yesterday. He said that this is a known issue with 11.1 and they are working on a fix, unknown ETA.

Like someone else mentioned earlier, pretty unbelievable given how many people use external monitors in a professional capacity. Luckily, I can get by with just the laptop for now but it's still a huge inconvenience.

I believe this is definitely a software issue. Up until this update my Mac was working fine with my Samsung 27in 4K screen. After the 11.1 update the screen is no longer even detected AT ALL. It doesn't even attempt to find it and offer the wrong solutions.

I've tried as some of the suggestions here including using displaylink and changing the displayport version from 1.2 to 1.1. (Only options on my screen) and nothing works.

The monitor WORKS FINE using my other laptop which is running older Catalina OS. I will not be upgrading that anytime soon.

It's incredibly frustrating this "bug" escaped beta testing and the attitude that they don't support external monitors is bollocks. I can't believe this is the official stance?!

Fix the issue ASAP Apple!

The good news is that one of the Benq ambassadors experienced the issue and reported that onto his YouTube channel. https://www.youtube.com/watch?v=4yJIea2UVp0&t=501s

I can't believe Apple will just discard that with "external monitors support is not our business". Even because companies like BENQ, LG and more collaborate with apple to design products dedicated to mac users (i.e. thunderbolt 3 support).

I am now into my 3rd docking station which has given me some improvements.

Setup:

Dual 2k monitor setup, HP Z27n G2

Monitors connect to docking station, docking station to computer.

1 monitor connected with Displayport (protocol 1.2)

1 monitor connected with USB-C (Displayport alt mode)

(Only way for Mac to see both screens due to lack of Displayport MST)

Docking station: HP Thunderbolt 3 120W G2 dock.

This setup work with my MacBook Pro 13-inch 2019

This setup does NOT work with my MacBook Pro 15-inch 2018.

Based on all feedback on the thread I too believe it relates to firmware but likely also drivers.

One major difference between my to MacBooks is that my 15-inch has a Radeon 555X GPU, hence utilising GPU switching.

As soon as I plug the 15-inch to the dock the OS freezes. Shortly after a signal is established with one monitor (DP) and then disconnect again. Monitor connected with USB C never light up.

Have notified Apple of the same

It may be an EDID problem.

Is there anyone using the CalDigit dockingstrations as sold via the Apple website and having the same problems?

Is there anyone using a dock supporting DisplayLink having the same problems (note that the DisplayLink website has updated downloads available)

Did anyone try an EDID emulator?

The only way I can get things to work is to use a HDMI cable and use SwitchResX for my Ultrawide MSI Monitor. Graphics a still grainy but workable. I have also had to go back to my 2015 iMac. The Display Port on 1.2 or 1.4 does not work for me. If I use a USB-C cable with a M1 MacBook Air, the Ultrawide Monitor does not wake from sleep. This is just a rubbish from Apple!

oh... WTF.

> Yesterday(+08:00) I replied here said "upgraded to 11.2 Beta (20D5042d) get issue resolved", but today I get worse, the issue persist, and even I cannot get the HDMI be 60Hz...

After I changed the resolution, from one to another, and then back to what I prefer. The HDMI working on 60Hz again .