macOS Big Sur - Multiple Display "Recovery"

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!!!

None of the work arounds listed worked for me and I require multiple displays for work. I corrected this issue with approximately $300 worth of new supplies from my local staples to include;

1. New apple brand thunderbolt cable (a different brand C to USB dongle does not work) $90.00
2. New HD monitor (lowest priced 24 inch HD with HDMI capability) $130.00
3. New 4K short HDMI cable (I did read in a previous thread the short cord made a difference for one user) $20.00

You may say this doesn't add up to $300 but I must take into account the four previous trips to the store for the new high resolution VGA adaptor ($50.00), dongle that didn't work ($40.00) and high speed HDMI cable that didn't work ($16.00). I will try to take back the dongle.

The good news is, it works now. Expensive little update. Thanks Apple

Very Frustrating after upgrading to big sur 11.4, it broke USB-C communication with Acer Monitor, the monitor shows no signal, but other devices connected via monitor are working are mouse, key board etc. I guess some New Developer Joined and broke the code ( commented USB-C ) functionality. :D

Very Frustrating after upgrading to big sur 11.4, it broke USB-C communication with Acer Monitor, the monitor shows no signal, but other devices connected via monitor are working are mouse, key board etc. I guess some New Developer Joined and broke the code ( commented USB-C ) functionality. :D — Maddy11 less than a minute ago

I have the similar issues here. After updating to Big Sur 11.5 on my iMac 27", 2017. The external Samsung Display (2 x C49HG9x) flickers. :/

I have the same issue. I have a 2017 27" iMac Retina running Big Sur 11.5. I have a 21inch iMac 2011 running !0.13.6. Apple Thunderbolt cable to a Thunderbolt to USB-C adapter. Trying to use my 21.5 inch mac as a second display and it is not working. This is very Frustrating as my wife needs the second display to do work. When are they going to fix this.

This is crazy. Apple Needs to fix this right away.

Having this same issue. A workaround that just worked for me was to:

• Open System Preferences
• Click on Displays
• If not already selected, select Scaled under Resolution:
• Choose a different scaling from the one that you current have selected
• Switch back to your preferred scaling
• If previously on Default for display, re-select that option

Once I switched back to Default (in my case), Mission Control started working as expected.

For reference, I'm running macOS Big Sur 11.4 (20F71) on a 2019 MacBook Pro 16 with a Radeon 5500M GPU. I haven't updated to 11.5.x yet because I use this laptop for DJing and upgrading is hit or miss for support with my mixer and DJ software.

Hope this helps someone.

Cheers, Flux aka Andy

Big Sur 11.5.2 here. Every time my screen goes off from power saving, resuming the computer will only detect 2 of my 3 external monitors, and I have to manually "detect" the third one myself each time in system preferences.

Come on, Apple, Big Sur has already been out for so long. Fix this mess!

Yes, upgrading to Big Sur will make your secondary display disappear from the display settings. To regain your display arrangement settings, do the following: (1) Install/Upgrade DisplayLink software (2) Reboot (3) Manually assign permissions to this software in Security & Privacy settings. Now count 1-2-3, and thank me later. Have fun!

I have two monitors on only one macmini, when I turn them off because I'm leaving my office, and turn the on when returning, most apps from 2nd monitor are now on 1st monitor. Not always all apps, but most of them, but not always the same apps.

super frustratiing and annoying. never had this with catalina.

same issue attached LG monitors apps all gather into my main window on my MacBook Pro M1 Max.