Big Sur 11.1 External Display Issues!

I've solved this (after two months of ****, switching resolution, changing port from left two right and back again), changing nearly everything: I bought a TB3 dock (in my case: HP Thunderbolt Dock 120W G2 since it seems compatible and affordable). Connected to my MBP 16" 2019 via Thunderbolt3 cable, connected my 49" ultrawide Philips 499P9H display with Displayport++ cable: worked like a charm with native resolution at 5120x1440@60Hz. The only caveat: the dock has a cooler fan. :/

Same issue! Basically my display preferences reset (and main display won't turn back on) every time my Mac goes to sleep.

Temp workaround for me: change Energy Saver preferences so the Mac display never turns off. Burns a ton of energy, but avoids the hassle of having to reset all my displays every time.

Display I'm using is an old 30" Apple Cinema HD Display, connected via Dual Link DVI adapter to USB-C.

Every time my Mac goes to sleep, it basically seems like the Display preferences get reset. It knocks the resolution of my Cinema Display down to SD, and I have to reset it to full res every time. Additionally, I keep my iPad Pro connected as a sidecar display, and while weirdly the sidecar display maintains its connection more reliably, the arrangement of it is reset every time the Mac goes to sleep.

In other words, the following happens when my Mac goes to sleep: Main display won't turn back on unless I disconnect/reconnect the USB-C adapter, the resolution preferences are reset, and the display arrangement preferences are reset.

I'm using a new Mac mini with Apple Silicon (M1 chip), so resetting PRAM isn't an option.

I was told by an Apple Technician on the phone that this is a known issue and should be addressed in the next MacOS update. Crossing fingers!

I'm having this issue from day one (release of macOS 11.1) and since then Apple Support is keeping me busy: I deleted preferences, bought a new thunderbolt cable (the original and expensive one from Apple ;-), tried different kinds of system reinstallations, rollbacks, system boots etc. Unfortunately with no effect. Even mac OS 11.2.1 did not fix the problem with my external 4K-display (USB-C). The only workaround that's working for me is to set back the monitor to display port version 1.2. With display port 1.4. the issue returns immediately.

I have 2 Dell monitors connected to my 2020 MacBook Pro 16". When I installed Big Sur 11.2 they both stopped working just like many others here.

After days of frustration, I found that if I switch the monitors to the USB-c hubs on the right-hand side of my MacBook instead of the left like they had always been, they started working again!

I also noticed that the top left USB-c hub doesn't recognize pretty much anything, including power... The bottom left USB-c hub seems to recognize power and non-display USB devices but definitely not my external displays.

Hopefully this also helps some others with display issues! It's incredibly disruptive to workflow when you're used to working with multiple displays and all of a sudden they are taken away...

The 11.2.2 update DOES NOT FIX the issue. I only have the original charger connected to my 16" MacBook Pro and the short Thunderbolt 3 cable that came with the monitor (Benq PD2720U). I have no hubs, nothing else. After the update it was even worse, either 800x600 or 1920x1080 maximum, sometimes it wouldn't even recognise the monitor, just like before. The only solution for me is to set to DisplayPort 1.2 from the advanced settings of the monitor. My other MacBook, which I didn't update and it's still on Catalina, has no issues whatsoever.

Just had this problem with a brand new Macbook Air 2020. Out of box with Big Sur (not sure which version), it worked fine with external Viotek 34" GNV34D (3440×1440 ), connected through QGeem USB C Hub HDMI 7 in 1 Adapter. After update to Big Sur 11.2.2 last night, computer no longer recognized the monitor correctly, believing it to be an apparently generic 17 inch 1920 x 1080 monitor. After trying a number of workarounds on this forum, none of which worked, I moved the HDMI plug from the HDMI 2.0 to the HDMI 1.4 input, and the GNV34D was recognized again.

I will not dare apply another update until I know that Apple has fully fixed this issue.

I've an iMac 27-inch (2017) and a Dell UltraSharp U2715H. Since I've updated the computer to Big Sur 11.2.3 I'm having problems with my external display.

It seems that it works correctly if the Display is on before the iMac is starting. If the display is off when the computer starts, then it will be never recognized although I unplug it or plugin again or even trying to switch off and on the display several times.

I need to restart the iMac with the Dell display connected and switched on to get it working properly again.

A firmware update to my Dell display seems to have helped in a similar problem with mini M1 Big Sur 11.2.3

DELL M3B106 Fixes & Enhancements 07 Jan 2020

- Adds new OSD option "USB-C Charging" to allow charging over USB-Type-C Port when monitor is powered off

- Fixes no display issue and no charging issue with some non-Dell notebooks or mobile devices

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.

Big Sur 11.3 seems to have fixed this issue for me with:

MacBook Pro 16' 2019 with AMD Radeon Pro 5500M 8GB

BenQ SW271

Now I'm able to reliably connect to my SW271 with USB-C at 4K 60Hz. Thank god Apple FINALLY did something to address it after a long 5-month period. This bug literally rendered my whole workspace setup unusable for such a LONG time. Hopefully Apple can improve its bug resolution time in the future, especially those related to hardware which make equipment worth thousands of dollars useless!!! This is definitely not the kind of experience I expect after investigating so much $$$ into Apple products.

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.

FINALLY! VICTORY! As of the latest Big Sur update my displays are now FULLY RESPONSIVE AND WORKING FINE. YES they come online after the computer goes to sleep. YES they maintain their arrangement and resolution.

Time to crack a beer and throw some dogs on the grill because it's going to be a beautiful 4th of July weekend y'all!!

MacOS Version that fixed it for me: 11.4

Can't believe it took this long, but my displays are now operating at 100%

In case anyone's curious: I have an M1 Mac mini, connecting two displays to it: 1) a 30" Cinema Display via adapter to USB-C, and 2) a Phillips 27" display connecting via HDMI. The 30" Cinema Display was the one that was giving problems before, not connecting after my Mac went to sleep, and losing the arrangement in the settings.

For those who experienced display connectivity issues w/Big Sur: update to 11.5 (just available for me today) and try again. I didn't have my HDMI working through all versions of Big Sur 11.1-11.4, just updated, and now have my HDMI / Thunderbolt / USBc to HDMI, for 3 displays on my Mac mini 2018, plus the advantages of the Big Sur improved performance throughout. Still, the older your display the greater the chances that drivers have dropped out / become incompatible. I'm having no problem with LG Ultrafine 4K 23.7, an LG UL600 27", and a Samsung 4K nu6900 TV all at 60 hz.

I replied earlier, I was blocked. Then darrenhumphrey suggested a new cable. I then recalled then that I had a similar experience with my Raspberry Pi4. I had been using a cheap adapter and cable on it, and high resolution would not work. I switched to a HDMI-micro to HDMI cable, problem permanently solved.

On my MBP, I was using my older Anker USB/Ether/HDMI adapter and an ancient HDMI cable. Result: kaka. Like the Pi, I found that issue (almost completely) resolved when I got a new cable. I bought a 4K USB-C/HDMI adapter and a 4K cable, and now it works. Sometimes the MBP forgets, but when it does, all resolutions are available in System Preferences::Displays and one click solves it.

To me that's about as good and A::B comparison as it gets. The only difference before/after is the cable, and this supported by a similar experience on a completely different system (Pi, using the same LG monitor). It may be a case of Apple actually being more correct with Big Sur in the age of all these new monitor resolutions. Hope it helps, people.