After updating to 11.1 external 4K Monitor is no longer working over 1080p

[panr]

Can confirm. Just updated my M1 Air to 11.2 beta 2 and display issues (randomly disconnecting and waking up with upscaled resolution) and BT issue are still there ;-( I'm loosing hope that this can be easily fixed by a software update...

Also, for some reason moving to clamshell mode is turning off the Air and display ¯\_(ツ)_/¯ What the hell is going on 😅

 

[oshogg]

Can confirm. Just updated my M1 Air to 11.2 beta 2 and display issues (randomly disconnecting and waking up with upscaled resolution) and BT issue are still there ;-( I'm loosing hope that this can be easily fixed by a software update...

Also, for some reason moving to clamshell mode is turning off the Air and display ¯\_(ツ)_/¯ What the hell is going on 😅

Well, it worked fine with Catalina and with Big Sur 11, so there is no hardware reason why this shouldn't work. It's a matter of getting the software/drivers right - so hopefully it will be fixed.

Osho

 

[maximlos]

Ah so still nothing, Apple knows this and we hope it solves before the release. Absurd, an incredible bug.

Apple does not understand that it is creating enormous inconvenience to professionals and graphic designers who must necessarily use the foreign monitor. Now they are cut off for a stupid bug, Apple technicians didn't notice this problem, but try them first?

 

[panr]

> Well, it worked fine with Catalina and with Big Sur 11, so there is no hardware reason why this shouldn't work. It's a matter of getting the software/drivers right - so hopefully it will be fixed.

Right, but we don't know what is causing the problem on M1. The same issue? My Intel Macbook Pro 15 (2018) works perfectly fine with the same display (the same OS installed). Only M1 suffers 🤔

 

[maximlos]

> Well, it worked fine with Catalina and with Big Sur 11, so there is no hardware reason why this shouldn't work. It's a matter of getting the software/drivers right - so hopefully it will be fixed.

Right, but we don't know what is causing the problem on M1. The same issue? My Intel Macbook Pro 15 (2018) works perfectly fine with the same display (the same OS installed). Only M1 suffers 🤔

not only that, on Macbook 16" same problem

 

[panr]

not only that, on Macbook 16" same problem

OK, so I guess that's a good news.

 

[skiabox]

OK, so I guess that's a good news.

Yes macbook pro 16 has the same issue so it is an operating system problem!

 

[Tellmesumtin]

I have a LG 43 UN 700B 4K HDR Monitor. But after the latest update to big sur 11.1 its no longer possible to use 4K Resolution... even with SwitchResX the resolution is unavailable....

I restarted and plug / unplug the monitor already several times but it will not work...

Somebody else had a similiar problem?

Fixed this issue by plugging in through HDMI cable instead of USBC. I have a 32" BenQ EW3270U. Scaled Resolutions options have returned. Not ideal but workable. A notice from Apple or BenQ would be appreciated.

 

[Tellmesumtin]

Damn, 😭I don't know what to do. I installed 11.1 yesterday without doing a backup. And now my monitor BenQ PD2700U doesn't work properly.

It's super weird, because first of all, my MacBook forgets the Arrangement of the Displays all the time. And at first, it was set to 1080p. There was no option to change any settings.

Thanks to DaveXX I just unplugged the cable dozens of times until I saw the "scaled" option again. Now, at last, I can set the resolution to 4k, however just 30Hz. This is kinda acceptable but what the heck.

When I don't use the monitor it all starts again. My MacBook just forgets the Arrangement of the Displays and I have to unplug dozens of times.

I cannot work like this. Any idea what I can do? Does it make sense to call Apple? Or do you know is it possible to downgrade to 11.0?

Just fixed this by connecting through HDMI instead of USBc. I use BenQ EW3270U

 

[maximlos]

Just fixed this by connecting through HDMI instead of USBc. I use BenQ EW3270U

we don't want to use HDMI, but directly through thunderbolt 3 (usb c -> usb c) the problem is that.

 

[threepol]

Just to follow up what I've read on the Apple Community forum (https://discussions.apple.com/thread/252174979?page=15), what did the trick for me was indeed setting the Display Port version to 1.2 on my screen (in my case LG 27QN880). After that, my screen showed the 4K resolution again in the settings. I could change it without any problems and it stayed like that. So while Apple fixes things, setting your Display Port to version 1.2 seems to fix it (hope al your monitors have such a setting available!)

 

[DaveXX]

Just to follow up what I've read on the Apple Community forum (https://discussions.apple.com/thread/252174979?page=15), what did the trick for me was indeed setting the Display Port version to 1.2 on my screen (in my case LG 27QN880). After that, my screen showed the 4K resolution again in the settings. I could change it without any problems and it stayed like that. So while Apple fixes things, setting your Display Port to version 1.2 seems to fix it (hope al your monitors have such a setting available!)

This is what i already said. But this fix not the problem it just improve it for some users (including me). DP 1.2 means it will reduce the bandwidth and it will not allow 4K60 with 10Bit.

If you have HDMI 2.0b it is currently the best solution because it can provide the full resolution and color depth of nearly every monitor (if you have 4K120 ofc you would need HDMI 2.1).

As i said after i got the HDMI Apple Adapter for free i have everything working (power delivery, usb-a and display at just one usb-c port). I can live with this solution by apple until they fix the problem.

 

[maximlos]

for example my monitor has hdmi 2.0 and now i am using hdmi adapter -> usb c but i can only get it to work at 8bit so it is not the optimal solution but the most that can be done in the meantime apple fix the problem (and it's taking so long for such a serious problem).

 

[DaveXX]

for example my monitor has hdmi 2.0 and now i am using hdmi adapter -> usb c but i can only get it to work at 8bit so it is not the optimal solution but the most that can be done in the meantime apple fix the problem (and it's taking so long for such a serious problem).

are you sure you use the correct cable? (HighSpeed or SuperHighSpeed HDMI) because usually every DP (over usb-c) or tb monitor provide a hdmi interface which is capable to offer the same resolution/color... (so at least hdmi 2.0b or even better). Its very seldom that a monitor has a DP 1.4 interface (doesn't matter if over usb-c or dp cable) and just HDMI 2.0a.

 

[maximlos]

are you sure you use the correct cable? (HighSpeed or SuperHighSpeed HDMI) because usually every DP (over usb-c) or tb monitor provide a hdmi interface which is capable to offer the same resolution/color... (so at least hdmi 2.0b or even better). Its very seldom that a monitor has a DP 1.4 interface (doesn't matter if over usb-c or dp cable) and just HDMI 2.0a.

This is monitor: https://www.benq.eu/en-eu/monitor/designer/pd2720u/specifications.html
can i use 10bit with hdmi?
thanks

 

[DaveXX]

This is monitor: https://www.benq.eu/en-eu/monitor/designer/pd2720u/specifications.html
can i use 10bit with hdmi?
thanks

Benq doesn't provide a good specification but this is a real thunderbolt display (not just display port over usb-c) which even support daisy chaining. I just wonder that even thunderbolt displays are affected.

Regarding the specs i could found it should have HDMI 2.0b ports (99% sure) so it should support 10bit. It's just important you use high speed cables (usb-c to hdmi high speed cable).

 

[maximlos]

Benq doesn't provide a good specification but this is a real thunderbolt display (not just display port over usb-c) which even support daisy chaining. I just wonder that even thunderbolt displays are affected.

Regarding the specs i could found it should have HDMI 2.0b ports (99% sure) so it should support 10bit. It's just important you use high speed cables (usb-c to hdmi high speed cable).

you can't find 10bit usb c hdmi cables, can you tell me one?

 

[DaveXX]

you can't find 10bit usb c hdmi cables, can you tell me one?

the cable/adapter should be certified regarding this standard and support 18Gbit/s:

Premium High Speed HDMI® Cable

Premium HDMI Cable Certification Program, HDMI cables for their 4K/UltraHD products that may include features such as 4K@60Hz, BT.2020 and HDR. Trust the cable with the label; HDMI 2.1b

www.hdmi.org

the best thing is the original apple adapter i got for free from apple because of this problem:

Apple USB-C Digital AV Multiport Adapter

The USB-C Digital AV Multiport Adapter lets you connect your USB-C-enabled Mac or iPad to an HDMI display, while also connecting a standard USB device and a USB-C charging cable. This adapter allows you to mirror your Mac or iPad display to your HDMI-enabled TV or display.

www.amazon.com

You can use a normal hdmi to hdmi premium high speed cable around 10$ and you have power delivery (charging via the macbooks power adapter without using another port) and one usb-a port.

there are third party adapters as well:

Anker PowerExpand+ USB-C auf HDMI Adapter aus Aluminium, kompakter, 4K 60Hz, für MacBook Pro, MacBook Air, iPad Pro, Pixelbook, XPS,Galaxy (Kompatibel mit Thunderbolt 3 Ports)

Power Expander + USB-C auf HDMI-Adapter. Der Premium-4K-HDMI-Adapter von Anker, Amerikas führender Lademarke – Schnelleres und sichereres Laden mit unserer fortschrittlichen Technologie – über 50 ...

www.amazon.de

or cables like this (4k60):

bauihr USB C auf HDMI Kabel [4K@60Hz], USB C to HDMI Kabel [Thunderbolt 3 Kabel] Kompatibel mit iPad Pro 2018, MacBook Pro/Air, Galaxy S10/Note 8/S9/S8, Huawei P20/Pro/P30/Pro, Mate20/30/30 pro (1.8M)

Das Merkmal des Bauihr Kabels von USB C auf HDMI

www.amazon.de

But with third party its always a little bit luck as well if they really support it correctly.

This is how it looks at my MBP 16 (usb-a go to a passive usb-a hub with 4 ports and as you can see power, hdmi and usb-a at one port):

 

[maximlos]

I tried 2 hdmi cables at 60hz 4k bought on amazon and connecting them to benq they go to 8bit, I asked the cable manufacturers and they also say that those cables are 8bit. Apple please resolve the thunderbolt 3 display issue! I can not stand it anymore.

 

[DaveXX]

I tried 2 hdmi cables at 60hz 4k bought on amazon and connecting them to benq they go to 8bit, I asked the cable manufacturers and they also say that those cables are 8bit. Apple please resolve the thunderbolt 3 display issue! I can not stand it anymore.

But this is weird. There is no 10Bit cable. Just imagine all HDR TV's need 10Bit for HDR or Dolby Vision. Every Xbox, Playstation is connected via HDMI and ofc support 10Bit.

It's just a matter of bandwidth the cable can offer.

Even in your manual its specified what you need for HDR/10Bit:

Make sure the player and the monitor have been connected via an appropriate cable:

• the provided HDMI / DP / DP to mini DP cable / USB-C™ cable / Thunderbolt™ 3 cable (if available)

• an HDMI cable that is HDMI High Speed or HDMI Premium certified

• a DP / DP to mini DP cable that is DisplayPort compliance certified

• a certified USB-C™ cable with DisplayPort Alternate Mode capability

You should maybe check the options at your monitor as well (e.g. hdmi rgb range or other color options). Could be some setting to limit this as well.

And as you can see at my MBP 16 with HDMI connection instead of my USB-C there is no problem with 10Bit:

 

[Marc G.]

Damn, 😭I don't know what to do. I installed 11.1 yesterday without doing a backup. And now my monitor BenQ PD2700U doesn't work properly.

It's super weird, because first of all, my MacBook forgets the Arrangement of the Displays all the time. And at first, it was set to 1080p. There was no option to change any settings.

Thanks to DaveXX I just unplugged the cable dozens of times until I saw the "scaled" option again. Now, at last, I can set the resolution to 4k, however just 30Hz. This is kinda acceptable but what the heck.

When I don't use the monitor it all starts again. My MacBook just forgets the Arrangement of the Displays and I have to unplug dozens of times.

I cannot work like this. Any idea what I can do? Does it make sense to call Apple? Or do you know is it possible to downgrade to 11.0?

As a temporary workaround, changing the DisplayPort settings in the monitor from version 1.4 to 1.2 fixed it for me.

 

[hardiv]

I was able to turn on the 60Hz option after clicking with alt-option on the text "scalable", after checking "show low resolution modes", below there is a list for refresh rate selection -> 60Hz works.

Cable: HDMI -> USB-C
Monitor: Dell U2718Q
macOS 11.1

 

[maximlos]

But this is weird. There is no 10Bit cable. Just imagine all HDR TV's need 10Bit for HDR or Dolby Vision. Every Xbox, Playstation is connected via HDMI and ofc support 10Bit.

It's just a matter of bandwidth the cable can offer.

Even in your manual its specified what you need for HDR/10Bit:


You should maybe check the options at your monitor as well (e.g. hdmi rgb range or other color options). Could be some setting to limit this as well.

And as you can see at my MBP 16 with HDMI connection instead of my USB-C there is no problem with 10Bit:

first point, wrong resolution (big sur fails to detect the correct specifications), monitor is 4k, color depth in theory that is 10bit, but via hdmi with this cable: https://www.amazon.com/gp/product/B075V5JK36/, i also asked the manufacturer and it is an 8bit cable.

in fact in the monitor screen it is unfortunately 8 bit

 

[Serenissimo]

As a temporary workaround, changing the DisplayPort settings in the monitor from version 1.4 to 1.2 fixed it for me.

Not for me with Macbook 16 and LG 32 4K

 

[oshogg]

Changing DisplayPort setting in the monitor from version 1.4 to 1.2 fixed the issue sometimes, but it doesn't fix the issue some time (for me). Even when it "fixes" the issue, 4K resolution is driven at 30Hz, and not 60Hz.

In my case (16" 2019 MacBook Pro driving 2 BenQ PD3220Us with Thunderbolt cables and 11.1 Big Sur), I found that the following method always works. This is with DisplayPort 1.4.

1. Connect the monitor to MacBook Pro with the Thunderbolt Cable.
2. If it isn't driving 4K 60Hz (which is the most likely scenario), open System Preferences-> Displays.
3. Click on "Default for display" under resolution. If that is already selected, click on Scaled first and then click on Default for display again.
4. Now, if 4K60Hz is still not driven, Click on Scaled with Opt key pressed. This will give a list of resolutions. Pick the resolution you want.
5. Then, click on Show low resolution modes. It should show the "Refresh Rate". If it is not showing 60 Hertz, it is likely showing 30 Hertz. Click on the selector to select 60Hz.
6. If 60 Hz is not available, Click on Default for display again and repeat the steps starting from #4.
7. After 2-3 tries, you should be able to select the right resolution and 60Hz refresh rate. If you check the monitor's OSD menu's information section - it should show 3840x2160@60Hz.
8. If after 2-3 tries, you are still not able to drive 4k at 60Hz with the right 'resolution', disconnect the cable and try again. Try different USB-C ports if one never works.

I don't know what's going on under the hood - but somehow, at some point, OS suddenly recognizes that the display can be driven at 4K 60Hz. After that it stays at 4K 60Hz until you put Mac to sleep or disconnect. After that, you may have to repeat these steps. I have chosen never to put Mac to sleep using Amphetamine mac app. And, I do not disconnect MacBook as much as possible.

This sucks and I hope that a real fix is coming soon.

Osho