Big Sur 11.1 External Display Issues!

I am experiencing the same issues. Very frustrating.

The workaround I've found is using my (active) TB3 <-> HDMI cable. This leads me to believe the issue is related to the Displayport profiles.

Really wish Apple would get on fixing this.

I was experiencing issues with my 4k 60hz Samsung monitor- terrible UI lag and videos were laggy. connected via a J5 create usb c to HDMI cable. this is how I fixed the issue; Click option while selecting scaling in the display menu and a longer list of resolutions should appear. select lower resolution and choose the same resolution you prefer, but in "low resolution" version. this does not degrade picture quality at all I find and brought performance back to smooth and normal.

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 .

Same Problem with LG QHD Ergo Diplay. USB-C only supports up to 1080. Switching to Displayport 1.2 its all right again.

Problem since macOS BigSur 11.1

Thanks for your tipp, would have taken me another 15min to try that. :)

I have been having similar issues with Big Sur 11.1

Upon boot my external monitor is recognized correctly and works fine. The problem arises after waking from sleep. My iMac (2020) does not see my external monitor and the only thing I can do is reboot the iMac, after which all is well until the next sleep. Apple tech support claimed it was because the display was connected to a Thunderbolt 3 dock (via mini display port) and not directly to the iMac. I tried everything other people tried (reset PRAM, reset SMC, etc.) to no avail.

What worked for me was to temporarily revert to Catalina. It ran for 4 days with no problems. When I rebooted into Big Sur the problem came back immediately.

Furthermore, under Big Sur I have been having problems with my wireless keyboard. It occasionally goes to sleep for a few seconds, not responding to keys. Then it wakes up and shows me all the keys I have been typing. No problems under Catalina.

Apple: I don't think Big Sur was ready for release!!!

I have the same problem, Mac Big Sur 11.1 does not recognize the external screen, I already tried with an HDMI and VGA cable but the problem persists, I think I am going to change it to Catalina

Does anyone know if the Mac Big Sur 11.2 beta version fixes the screen problem?

@hellamasta I had the issue about 3 weeks ago, so I'm now 3 weeks on Catalina again and have no issues.

Probably important: I am on a MacBook Pro 16" i7 and did a complete fresh installation of Catalina. Thanks to the container format APFS I was able to move my files without a full TimeMachine recovery from the old partition. So I startet with a completely clean installation.

Sadly Catalina behaves as sluggish as before on the MacBook Pro 16. But that issue existed before when I bought the MacBook and seems to be in the systems nature.

problem for my MacBook Pro started today (19 Jan 2021), I updated to Big Sur 11.1 a couple of weeks earlier... Now, if I connect external display, even with lid open, I all my displays (external + internal) go blank. Cannot see a thing, until I unplug the HDMI cable (via apple usb-c connector). I have tried all sort of things: changing HDMI cable, converters and also many of the tricks and tips listed above.... no resolution.

from iPad I checked external display, everything fine.

Last week, my HomePod gave in.. on Big Sur, it wouldn't work (no sound at all). My Service request still pending, Apple folks even asked me to reinstall, but in my heart I don't think they would cut it.

Big Sur is a bigger problem. I can't imagine how the QA was done, standards have gone down a lot.

I wish I could go back to 11.0.1, everything was working fine.

I switched back to Catalina. I waited a while (to take my own advice) before jumping on here and giving false hope. That being said, so far, Catalina is working GREAT. I have had zero display issues, not to mention my monitor/computer wakes up MUCH faster while in clamshell mode (simply plugging in a USB-C cable). 3440x1440@60Hz every time. Catalina doesn't feel any slower to me over Bug Sur.

How did you switch back to Catalina? Did you have to wipe your disk clean, reinstall Catalina then restore using TimeMachine?

Or were you able to reinstall Catalina by booting into the Rescue drive partition which supposedly does not delete anything?

While I want my external drive back, I don't want to make things worse than they are.

I just did it old school - I zip up my Music, Downloads etc and do a clean install, which gives me a clean Library folder. I downloaded Catalina installer on an old Mac mini, created a usb stick, used disk utility to delete/create partitions and re-install. My Documents and Pictures folders are in iCloud so that part is easy. I use Firefox which restores browser bookmarks and plugins.

I have decided to buy a 2TB drive and back up my Mac afresh and then reinstall Mac OS X Snow Leopard. You might want to do the same.

I have had too many issues since upgrading to BigSur last week, Even restarting and opening files is too slow. My Mac won't recognize my external drive or my external Snowball Mic. Even signing in to this forum was a pain when I clicked the link in the email as instructed.

I think Apple is smart setting up these forums. It is using us as the guinea pigs to pinpoint the bugs that they should have found first before release.

Are you listening, Apple?

Here you go:

OS X Daily: How to Downgrade macOS Big Sur to Catalina or Mojave

How to Downgrade macOS Big Sur to Catalina or Mojave

Posted: 08 Jan 2021 09:33 AM PST

Did you update to macOS Big Sur but now wish you hadn’t? Are you no longer interested in using macOS Big Sur on your Mac? Perhaps you installed it to try out all new features and changes, but you’re not happy with it due to app incompatibility, performance issues, or some other problem that you ... Read More

I have the same issues since upgrading too (on my MacBook Pro 16). I have 3 monitors plugged in externally using different USB-C adapters and have been having various problems since upgrading last week to Big Sur. Good to hear that it isn't just me, but wish Apple would fix them. HDCP has completely stopped working on one of the monitors and I can no longer get 4K on my Benq PD2700U. But if I reboot into Windows (I have bootcamp) all the monitors work fine. So now I have to reboot into Windows just to watch Netflix.