Big Sur 11.1 External Display Issues!

I solved a similar issue with a new hdmi cable specifically rated for 4K or better. My old cable, which worked fine until I updated to big sur, suddenly gave me intermittent results. .

Have you tried to open Display Link Manager and enable the option "Launch app automatically after logging-in"?

I have a MBP 16'' 2019 with an ACER XR38 and can confirm.

Big Sur 11.1 has this issue.

Big Sur 11.2 (beta) has this issue as well. I couldn't continue working with a 30hz external monitor so went back to Catalina.

However, my biggest reason to downgrade to Catalina was Big Sur's unprofessional Design Language. Ugh.

I've found that most of the time I can get back my Samsung Odyssey G9's native resolution by unplugging and replugging the display if, when the laptop (16" MBP) wakes it's reverted the resolution.

Today, that wasn't enough and I also had to open displays preference and re-select "more space" or option-click scaled and select 5120x1440.

I am getting 60hz refresh according to my monitor. Though it is capable of 240hz, I don't think the MBP is up to that.

Update: like some others have mentioned above, I was able to get my 42" LG 4k monitor working again by using an HDMI via USB-C dongle instead of direct USB-C from monitor to laptop. The display settings are a little weird in that it doesn't let you select the resolution or refresh rate at all (as it typically does) but only allows you to select the scaling level. Seems to be working fine otherwise.

That's why insist, everyone, I repeat, everyone shall report this to Apple as I did.

In this thread there are so many posts complaining about this issue but only a few stating that they actually reported it to Apple. For me Twitter was a start point as I didn't have a phone number and I didn't want to go to an Apple Store with a trolly carrying my gear. People angry for weeks due to this issue. Report it, put pressure on Apple, get it fixed and happy days.

Navigating on https://getsupport.apple.com/ you can find a link for a callback from Apple, and yes, they do call. Even though there is a link on top right of this very page.

Totally agreed. I downgraded and even swapped out my current graphics card (W5700X) for the original one that came with my Mac Pro (580X) that has only ever been used with Catalina. The problem persisted on both cards regardless of OS version after updating to 11.1. I even dual boot to keep my media/music software separate as it takes a while for the software I use to support a new OS version. Firmware is the one thing that can mess up both partitions and this is the case here.

They'll never do it, but the professional users really need a way to roll back firmware.

Interested to know if this works for anyone else...

I posted a while back with the same issue. My monitor was not detected at all. I tried a lot of the solution offerings here and made up a few myself... and I can tell you it doesn't matter what side of the mouth you hold your tongue 👅

Incredibly I have now got my monitor back online with full resolution. I'll caveat this by saying "I have no fricken clue how this works and it doesn't make sense AND i can't even be sure what combo I did of the following but it works for me". I'm obviously reluctant to repeat the scenario incase the voodoo stops working and I lose my monitor again. So, it'll be interesting to see if this works for anyone else.

I think I took the USB-C cable for monitor out

I went into System Preferences >> Displays

As per someone else's instructions I tied to get the option to see all possible display resolutions.

https://osxdaily.com/2015/08/27/show-all-display-resolutions-external-screen-mac

I know the scale options never came up no matter what keys I was pressing but it was flicking between Default and Scaled

In the end I think I left it on Default.

Voodoo part... I then plugged my external monitor in and it was detected. WTAF

I then went back to display settings and bumped both of the resolutions to max and it worked fine.

I lost my monitor again at some point for no apparent reason and so did this tom foolery again and it worked.

If the community could give it a go and post back their steps if it worked maybe it'll help.

This is a horrible 'feature' and I feel for the community.

Mac OS Big Sur 11.1

Fall 2018 Mac Pro 13in

Samsung 4k monitor

Good luck

Thanks man! That did the trick for me. This is a really annoying and strange issue. What helped for me a while back was:

• unplugging the monitor;
• creating a new user account;
• plugging in the monitor;
• logging back in to my own account;
• then the issue was fixed.

However, your solution is a whole lot easier. Hope it stays correct now.

I filed a complaint initially through Apple Support (my MacBook is covered under AppleCare still) and today through https://www.apple.com/feedback/macos.html

I have the MBP 16" and two BENQ EW3270U 4K displays. Formerly using USB-C cables with no issues under Catalina. With Big Sur I've been playing the "have you shut it off and on again" until at least one of the displays comes up in 4K HDR mode. The problem is I want both displays in 4K HDR and if one changes mode, they all change mode, and we're back to square one. My particular monitor doesn't support changing the DP version that I can tell (I think it uses DPv1.2 anyway), and HDMI doesn't support the full 10-bit YCbCr4:4:4 mode at 60Hz.

As a caveat, it works perfectly, every time, when I boot into Windows 10 Bootcamp, full 4K HDR on both displays with the same cables, no fiddling required. Makes be want to just uninstall macOS altogetherwith and maybe kick Linux around...

As for me, there is still only one solution. I am using this old (but still functional) app from App Store that enables me to work with 4K (2560x1440 @ 60 Hz). MBP 16", BenQ SW271, USB-C to USB-C cable. Sometimes after rebooting the cable needs to be unplugged and plugged again and the monitor goes blank and wakes up. But it works!

Shame on you Apple! Proffesional lives matter! We are real people not the fancy-pants designers from your ADs.

https://apps.apple.com/cz/app/display-menu/id549083868?l=cs&mt=12

I have a late 2015 iMac 27 inch retina and have been using a HDMI cable without full resolution on my second ultra wide 34 inch MSI monitor since BigSur landed. I also have SwitchResx installed. I changed cables to a miniDP to DP and it must have tricked the system as now I can see a full suite of resolutions in SwitchResX. But when I move above 3440x1440 the second Monitor pixelates. At least I can see all resolutions in the list now for the second Monitor with is a 5k2k type with a LG panel. I couldn't see this before with. Above 3440x1440, the ultra wide aspect is not working as the Monitor thinks it is 27inch. This proves it is an Apple bug within BigSur. It also shows that the bug has to do with HDR as any resolution with HDR on does not work. I trying without HDR on and see if it helps. The new cable I tried is this one: https://www.amazon.com.au/gp/product/B0140QEYEW/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I'm just sitting in front of it: it take slonger to synchronize (about 10-15seconds). Over DP it works constantly stable with macOS11.2. All the time the same (full native) resolution, no more 720p ****, this solution works for me. It's a shame to have a 160€ TB3 dock for such a simple task.

If we want the problem to be taken seriously, there must be a lot of us putting the maximum pressure on Apple.  So there are at least two things to do:

1- Contact customer support

2- Report the bug: https://www.apple.com/feedback/macos.html

Please, everybody, do both: call and write!

I have found a temporary solution.

I had the same problems as everyone else with my Benq SW271 external display: incorrect resolution, refresh rate limited to 30 Hz instead of 60 Hz, poor image quality. My screen was plugged in with a usb-c cable. Today I used a Belkin usb-c to hdmi adapter and it works fine (4k and 60Hz). 

I know this is just a workaround and the real solution has to come from Apple. So we still have to continue to put pressure on Apple by calling customer service and reporting the problem here: https://www.apple.com/feedback/macos.html

[Edited by Moderator]