macOS Big Sur - Multiple Display "Recovery"

I've found something thing macOS Big Sur broke - the "recovery" after changing display sources. Let me explain...

I have one big 4K monitor, connected to both my Mac (USB-C) and my PC (HDMI). I switch between the two sources on the monitor depending on what I'm doing. Each computer also has its own dedicated monitor (built-in for my Macbook, an old external for my PC).

Prior to macOS Big Sur, if I switched to the PC input on the monitor, all the macOS windows would shift over to the built-in laptop display, and then shift back to their correct window once I switched back. They no longer do that.

The application all stay on the laptop screen and the big screen is empty when I switch the source back on the monitor. I then have to move everything back to the big display.

I guess that's better than the PC behavior where even if you switch the source on the display back to the Mac, Windows still thinks its connected and continues to extend the display (the fix for that is to go to display properties and select "only show on display 2") , but thats a whole other gripe.

Has anyone else experienced this as well? Is there a setting I'm missing? Should I file a bug report?
  • I am just as frustrated. Brand new Samsung monitor and it is not working on Big Sur 11.4. Black border on each side. Same monitor works great on a Catalina Machine. @apple please fix this.

  • I have a problem with my second monitor connected to HDMI on Mac Mini M1. Before the update of 11.4, it was working perfectly. I just recently updated the OS and now it takes time for my mac mini to detect the second monitor. Sometimes, I have to remove the HDMI cable and connect it again for the display to work again.

    Please @apple fix this problem.

  • Same issue! After I upgraded my Mac, my hi-res HTMI-connected Samsung monitor streaked and blipped. The windows also jumped around when it would wake up. I had to unplug the Samsung and now it's worthless and collecting dust. I plugged in an old monitor with a VGA cable and the dock and menu still do not work on the second monitor. Luckily, I have not upgraded at home. ...I use three monitors there. I'm a graphic designer. I NEED multiple monitors. Apple, FIX THIS MESS!!!

Replies

Yeah, I'm having the same issue as others who are here in November 2020 (the day after the release). Definitely regretting updating entirely now because trying to teach all from one small monitor (when both me and my students are used to me having two monitors) is ruining my lessons. Is there any fix out there or any possibility of this being fixed before the weekend is over and classes resume on Monday? The is extremely frustrating because one would think this kind of issue would be caught in their "extensive" beta process.
Same here after updating to Big Sur. As soon as I connect the external monitor, all my apps are somewhere off-screen. I have to use Mission Control to drag my apps to the laptop screen to access them again. This is quite a nuisance.
Updated to Big Sur today. I have a 2018 Mac Mini running dual monitors. One monitor is USB-C, the other is HDMI. The HDMI monitor will not work, regardless of every reset over the last couple of hours. I’m regretting updating as I really need both monitors right now...
Same here, can we get a fix for this!
Updated to Big Sur...

Unable to get the HDMI port of my 2018 Mac Mini to work. Tried all the resets and configurations.

My 3 monitor setup:
  1. 4K HDMI

  2. 4K USB C -> DisplayPort

  3. 4K USB C -> DisplayPort

Today, the DisplayPort monitors work fine as they did yesterday on Catalina, but the HDMI port is a no go.

Help me, Obi-Wan Kenobi...
Same issue here. What I found is that I can see the window using CTRL Down Arrow for Expose. Then I can drag the window over to my laptop screen and then exit expose and then drag the window back to the external monitor. Not a solution but in case you need a workaround.
Did anyone find a solution for the HDMI issue beside downgrading to Catalina ?

same issue. Extended monitors no longer work..... will think twice before updating so early.

pls pls pls FIX
I have the same issue. If you want a quick fix this is what helped for me. Use a USC-C to HDMI dongle till the fix is out :)
I had the same problem on 2018 Mac mini, and (maybe just luck) changed the HDMI cable and it's working fine. USB-C monitor and HDMI monitor working as expected.
UPDATE: 9:21 EST - Working now.....

Same issue. Running two monitors. USC C-HDMI working, mac mini 2018 HDMI not working. please fix before monday, need second monitor and dont want to have to buy another usb c-hdmi
With the new Big Sur update, my iMac’s secondary monitor hooked up through USB-C to HDMI adapter stopped working. I was able to get the monitor on by using mirror screen, but I cannot use as an extended desktop. All beta versions leading to the latest version worked without issue. This should be worked out before final release.
I have a Mac Mini 2018 with two monitors. After upgrading to Big Sur the monitor plugged in with a USB C to HDMI converter was recognized, but the one plugged directly into the HDMI port wasn't. Turning the computer off completely and then restarting fixes the problem for me, but it's happened a couple of times now and is really annoying.
I am having the same issue, wish I never updated this early. It seems like most people are having issues with HDMI, my display cord is a usb-c to usb-c and its still not working. It seems now the only solution is downgrading to catalina...
I have two 4K monitors that worked seamless prior to Big Sur. One has stopped working altogether with no apparent settings to reinstate the monitor. I have the highest end Macbook Pro on the market, so graphics card isn't the issue. I'm on MacBook Pro 16-inch 2009, 2.4 GHz intel 8 core i9 with 64gb 2667 MHz DDR4 ram and AMD Radeon Pro 5600M 8 GB graphics card with 8 TB SSD hard drive. Which is the top configuration. There are four Thunderbolt3 ports, designed for 4K power. I am using two for 4K monitors, 1 for hub and 1 for external hard drive. It seems to me this is a driver issue around batter power regulation that is defaulting to turn off the additional 4K monitor. I can't find a solution to this online yet and this has interrupted my workflows. Very annoying since I paid so much for the highest spec machine.