Big Sur 11.1 External Display Issues!

Wow after reading a portion of these entries (no I don't have the patience to read all 40 pages) I am thankful that my issues are less severe, although still seriously annoying. I have a late 2020 iMac, intel i7, came preinstalled with Big Sur, which I updated to 11.2.3 before attaching my 2 identical LG 27" 1080p monitors via a 3rd party USB-C/TB3 to HDMI cable. The system finds the monitors, which I now discover apparently isn't a given, but randomly after sleep/lock one of two things happens. Either the display arrangement changes, or the screens swap.

My arrangement is <LG1><iMac><LG2>

First problem: after waking my display arrangement may be <iMac><LG2><LG1> or <LG2><iMac><LG1> or some other variation. I have not noticed any consistent pattern here.

Second problem: after waking my display arrangement will remain <LG1><iMac><LG2> BUT all the apps on <LG1> have been moved to <LG2> and vice versa so that while the display arrangement is the same, the screens are essentially swapped.

As an added bonus, the "snap to" function while trying to rearrange the displays is finicky making moving things back and extra fun challenge since half the attempts just drop the screens back to where they were rather than letting me change the arrangement.

You may have already tried this--after you go to Display>Arrangement and reestablish the order <LG1><iMac><LG2> (by moving around the displays shown in Arrangement and overcoming the finicky "snap to" resistance--I've encountered this too)--or if they did remain OK in the proper order--click again to highlight the display you want to be your primary display in Arrangement. After the highlight appears around the display, the dock and icons may move back to the monitor (iMac if that's your chosen hub) you expect to see them at. But yeah, for many of us, not all the displays can be found in Big Sur. Plug and play ain't what it used to be.

Thanks for your response. My primary display is the iMac and for whatever reason that element remains constant. The white bar does not migrate with the rest of the changes, nor do the applications open on that screen ever become reassigned to one of the other monitors.

Okies. I see you said the apps switch is between LG1 and LG2. If you can display two monitors plus the iMac that's golden.

I don't recall anybody in those 40 pages reporting problems going from one 11.2 updates to another. We hit them earlier--still backups are good before updating. Apple support more or less advises me if the usual resets don't work after I've lost displays or peripherals and I can't live with what I have then a good bet is to use Recovery mode and go backwards. Personally even tho I lost the HDMI port Big Sur feels more stable than Catalina.

I bought this with Big Sur installed so I don't have a back up to go to. Given the host of problems I have had with Big Sur (these are only one subset for sure!) the fact that Catalina seems to you to be even less stable is tragic/scary/unfortunate.

Too bad you've had problems. Before updating you could backup your 11.2.3 with Time Machine to an external drive in case 11.2.4 is even worse--and one of the Recovery Mode options I think is to reinstall the OS that came with your device. Catalina was finicky for me After one update my Mac refused to output audio to the set output device for any movies displayed on my 4K tv--it insisted on using the TV speakers!

We hope that with 11.3 (the final version ... since we are at beta number 8 ...), it solves this annoying problem, in my case I have temporarily "solved" by setting the DP on 1.2 of my Benq pd3220u attached via tb-3 to the 16 intel macBook pro, but I think it is a "patch" not a real solution...

I didn't have your issues as I said a while back--but I fixed the issue I had (for now) of non-HDMI port recognition of external display--by resetting the SMC--a tip from MacRumors discussion. I thought I had tried this before but gave it another shot. Shut down the Mac, pushed the start button for 10 seconds (I think it chimes) keep it pressed down, then release, then press to start. I left the tv connected to the HDMI on throughout for this try. When the Mac Mini restarted it now recognized my third display.

When I tested by doing a simple restart the recognition held.

So maybe resetting your SMC will fix the issues you are having too.

Same issue here - all fine before the update, I have a BenQ 27" 4K screen and its max capability is currently 1080p which is unworkable. Tried reinstalling, unplugging, a different cable, turning HDR off and don't get me started on the high dynamic range.

Unacceptable Apple.

The SMC reset noted above stopped working for my Mac Mini 2018 and again I lost my HDMI port--down to 2 displays: 1 T3 and then 1 USB-C to HDMI. Trying to reset the SMC cleared out desktop settings to default and maybe disabled Microsoft Edge and prevented screen sharing w/Apple support to troubleshoot. But still no HDMI. And the USB-C handshake required restart of the Mac and the 2nd display (Samsung 4K tv) and reconnecting cables so jury out there too.

I spoke to Apple tech support one or two days ago--the support person said Apple has not recognized a problem with Big Sur connectivity to external displays and hasn't provided any guidance to their support teams. That's what that one person told me.

Hello all. When upgrading to 11.1, I too lost my external display. It fixed some time later after multiple resets. I take my MacBook Air (M1) with me daily and today I discovered something I can duplicate and I hope this helps. It had re-occurred off and on as I updated to 11.2.2 as I have now. It has been quite annoying.

I use a Thunderbolt 3 dock and a Wavlink 3 dock. One at home one at office. Each has an external G-Drive 4TB high speed drive for working files. I carry a small 1TB SSD with me to take work home. We also have a NAS that is mirrored. Yes all of this is overkill, but...

My UPS failed yesterday while the power company replaced the transformer for our street. Upon rebooting the external monitor stopped working. After several attempts to get the screen back something worked. I did it again just to test and it does cause the issue. I tested on my wife's air and same thing. She has a hyperdrive dock and we had to switch between HDMI and Display port and back as well. Not sure why a USB drive locks up an external display path, but since it is all crammed on the same high speed USB pipe I guess stuff happens.

If the power fails, the G-Drive is not ejected properly. Upon power up, the external display does not work. If I power everything back off, disconnect the G-drive, and then restart the MacBook Air and plug the dock back in everything works. I can then plug the G-Drive back in.

This is the first time I could replicate both the failure and the fix. Of course I just bought the biggest UPS that the local e-waste store had in stock.

I hope this helps at least one of you!

Cheers

Breakthrough today! 11.2.3 a few weeks ago got me to *much* more reliable re-connect with full 5120x1440 resolution on my Samsung Odyssey G9 from my late 2019 16" Macbook Pro when the macbook comes out of sleep, this with a USB C/Thunderbolt->DisplayPort 1.4 cable (For 5120x1440 you need DP 1.4). I found this annoying because it means two ports on my macbook are consumed, one dedicated to the monitor and the other going to my Pluggable Thunderbolt dock that supports DisplayPort 1.4. When I did get things working again with 11.1/11.2 I had to turn off adaptive sync on the G9

Now, today, I was looking at the samsung website because I was working to attach a VESA mount to my Odyssey G9 monitor and found they released new firmware for the monitor in Feb. I took a chance and installed it. Voila! DisplayPort 1.4 cable to the Pluggable Thunderbolt dock and I'm back to a single thunderbolt umbilical cable to the Macbook! Further, I was *also* able to re-enable Adaptive Sync

Looking at what Samsung says, I suspect they updated support for AMD FreeSync which is used by the Radeon Pro 5600 in the macbook pro.

Hello,

I have just updated to 11.3 and FINALLY they've fixed it !!!

My USB-C to DisplayPort adaptor finally works again with DisplayPort 1.4 at 4K 60Hz and with HDR.

I have a 2019 MacBook Pro 16' and an Asus 4k 60 Hz HDR monitor.

It finally works again for me.

It is good that your USB-C to DisplayPort adaptor works! I have a Mac Mini 2018 and I never had a problem with a USB-C to HDMI connection on my Mac. However Big Sur did knock out my HDMI port. And 11.3 does not fix that issue. So I would advise Mac Mini 2018 and even Mac Mini 2021 M1 owners and owners of other Macs that have reported HDMI issues to back-up your Catalina before updating to HDMI if you need that HDMI port for an external display. 11.3 may not do it for you.