Big Sur 11.1 External Display Issues!

Upgraded to Big Sur few months ago with no issues. Recently I have installed the minor update macOS 11.4.1 and after that my 4K Type-C monitor (LG UN880) is showing “no signal” error with no picture although the keyboard and mouse which are daisy-chained through monitor still working. Please help!

This is really a long thread. I have a 2020 Intel T2 Macbook Pro, and a Dell 3008WFP (very similar to Apple's old 30 inch Cinema Display). It has worked well with several Macs, and this Mac connects nicely to a Monoprice 27 inch HDMI. Alas, the Dell offers only limited resolutions, no more than 1920 x 1200, but what is worse is the image on the display is cropped (no menu bar, no dock, but "hover pop ups" are visible from where I infer the dock to be). 90 minutes of collaboration (lots of rebooting, serial disconnection and reconnection of cables, NVRAM & SMC resets, safe boot) with an Applecare Senior Advisor left with a long list of über-tedious things to try. I am using an Anker hub with HDMI (works fine on the other display). My question for readers of this thread is "Has anyone successfully bypassed such nonsense by using a different interface, for example a USBC/TB3 to DisplayPort cable?"

I’m using a LinkUp thunderbolt 3 hub and it is working very good. However, if I try another hub, the issue comes back.

I personally found LinkUp hub a good solution and in parallel I’m building up a desktop windows based PC. After 20 years of Apple I can’t accept as a professional, to waste months in fighting to solve the issues they introduced, doing nothing to get them solved!

It works!! The Warrky 10 foot Thunderbolt 3 to DisplayPort cable solved all my problems. I get full resolution without cropping. Hooray, and not an expensive solution at $18. If I paid myself minimum wage for all the hours of troubleshooting I've done, I could buy a big handful of these cables.

If DisplayPort is an option for you, try it. If not, let us hope Apple's engineers will soon cure the HDMI implementation of all the head lice and scabies Big Sur seems to have given it.

Hi,

I have a Macbook Pro 13 2020 and two LG 27UL850's. One is connected via USB-c to the Macbook directly. The other is connected to a Dell dock. The Dell dock is connect to the Macbook via USb-C. Prior to Big Sur I could use the Displayport connection on the Monitor. Now I have to use HDMI.

I would like to switch to DisplayPort, but when I do the screen goes black. Switching to DisplayPort 1.2 doesn't seem to work. Any help would be appreciated.

To those of us with LG 32DU99s connected via usbc, how’s the latest update treating our monitors? I been sitting pretty on 11.3.1 and dare not to upgrade until I can confirm I’m not going to lose my monitor for who knows how long again.

That’s unfortunate. I went ahead and updated to 11.4 and my LG 32DU99W like others have reported still works via USBC, knock on wood. @Triny D, you should report your monitor models to prevent others the headache, just a suggestion and hopefully Apple decides to dead this issue once and for all.

I think something is wrong with the 11.4 update, too.

(MBP 2019 with external BenQ SW271)

There's some kind of glitch when I view images on Photoshop, in that I can only see a giant block of bright green on the entire files. It is intermittent. When I restart, it seems to go away, and the problem then returns later on. This was happening during the 11.1 update, then it seems to have been repaired in 11.3, then it returned in 11.4. I did not have this problem before 11.1.

It could be Photoshop did not update yet. Who knows, they have a world of problems of their own. But Photoshop wasn't the one that glitched my external monitor in 11.1.

I am having the same issue with a 2018 15 inch macbook pro connected to a Samsung 50 inch 4K TV via USB C to HDMI adapter. This setup has worked flawlessly for two years, until I upgraded to Big Sur last week. Now when I plug in, sometimes it only offers me 1080P and instead of identifying the display as a Samsung, it just sees it as "Display".

This is severely impacting my workflow.

Come on Apple, fix this problem or at least give us some feedback that the problem is being worked and when it might be fixed. I'm still running Catalina on my MacBook Pro 16" 5600M with two Apple Thunderbolt 2 Displays (daisy chained) because I refuse to upgrade to Big Sur and not be able to use my Apple external monitors. The way it's looking, I probably won't get a chance to use Big Sur if the problem doesn't get fix prior to Monterey becoming available. Pretty sad.

Well while on 11.4 today my monitor (LG 32DU99W) randomly went back down to prefix resolution, 1080p max, and not even installing Catalina fixes it this time. Guess I’ll be selling this thing before it loses more value and see how the updated 16s handle externals 🙄

Hi, curious to know have you got it to work?

I just got my MSI PS341WU monitor today, and is about to get an M1 Mac Mini, but seems like there are lots of issues about it.

So... any information would help, thanks!

Hello. I'm note sure if my problem is the same. My MacBook Pro i9 slows down terribly when the external Monitor, a Samsung is connected. I had some issues already before installing Big Sur (11.4), but now it's very noticeable. Cinebench R23 drops from around 8000 to under 1000 when running it multiple times with the external screen on. Software including the Finder goes very slow and nearly non reactive after a short time.

This is not the typical upgrade complaint that is noted for external displays--users have reported issues with display connectivity or display resolution settings, not as far as I can tell Cinebench / CPU / GPU scores, and certainly not Finder issues. Although I lost my HDMI port for my Mac Mini 2018 on Big Sur my Finder and overall OS X speed and responsivity subjectively improved with Big Sur--Finder speeds, file copying, reboot etc. Perhaps a third-party conflict (or even malware that coincided with your upgrade?) is slowing your Mac down. Have you tried Disk Utility / First Aid for possible disk errors, checks for virus and malware, and / or reinstalling your 11.4? Is there possibly an updated driver for your Samsung? I have a Samsung 4k tv nu6900 43" TV hooked up to my Mac mini--I don't game with it or use it for graphics intensive apps (only streaming), but it's performance improved with Big Sur--again, subjective, but looks better with such AppleTv etc. -- no video issues.

My MSI Optic AG32C gaming monitor is working fine except there is no audio. It works fine on my Windows laptop but that has an HDMI jack so not surprising. I'm using a Belkin HDMI to USBc adapter I just bought from the Apple store, since there was no Apple adapter of this type available. From what I can see of MSI, there is no listed support for any Apple devices; there is only mention of Windows support for this peripheral. Support at MSI puts me on hold forever. Guess that means I need to call Apple Support or bring the monitor and laptop into the Apple Store. Maybe I can get the AirPlay to work. So far, that doesn't work, either.