Big Sur 11.1 External Display Issues!

Turn it off and on again!

I spent ages reading posts and fiddling with my MBP 2019 16" and BenQ EW3270U.

Just turned the monitor off and on again and the situation had righted itself completely!

Unless Apple have slipped an unnoticed fix in during the night...

I'm experiencing a similar problem.

My external Dell (SE2719H) monitors no longer work following the Big Sur update. I'm using a j5create USB to Dual HDMI Adapter to connect the monitors to my iMac USB 3.0 port. The following is posted on the j5 site:

"Attention macOS® 11 Big Sur users: j5create USB™ Display and USB™ Ethernet adapters are not currently compatible with macOS® Big Sur 11. To avoid loss of functionality with the j5create USB™ Display and USB™ Ethernet adapters, we advise all Mac® users to delay updating to macOS® Big Sur 11"

Obviously, I was not aware of this issue prior to updating my OS.

Does anyone know of a work around until they fix the bug?

You can find another thread here (https://forums.macrumors.com/threads/after-udpate-to-11-1-external-4k-monitor-is-no-longer-working-over-1080p.2275376/page-2?post=29413261#post-29413261)

Have a MacBook Pro 16 (2019) with a monitor BenQ PD2700U that doesn't really work, unless I unplug all the time and it is still only in 30Hz.

Do you guys think that Apple has noticed this bug?

I too am having the same issue after 11.1 update. I first noticed my mouse was jerky, and quickly realized it was the monitor refresh rate of 30hz. If I reboot my computer while plugged in, it seems to work correctly until I disconnect and reconnect my USB-C video cable. Quite annoying when switching to my external monitor to have to reboot every time. Apple, please fix this issue ASAP.

I have an LG 34WN80C and nothing changed other than the 11.1 Big Sur Update.

Same issues on Big Sur 11.1 on 2019 MBP 16" with an LG 32UD99 32" 4K display connected via USB-C. Worked fine on Big Sur prior to 11.1 update.

Interestingly, I have an older 2016 MBP that works just fine on the same monitor with the same settings, also under 11.1.

I can enable/disable Displayport 1.2 (not 1.4!) on the monitor settings, makes no difference.

weird issues here too on mac mini dell ultrasharp 49", after update the lowest res was the default selected and i cant even use the one i previously using. direct usb-c to usb-c. all the options. highest resolution is now 38xx.

I had the same issue. I spoke to an Apple tech rep about two weeks ago (early Dec 2020). The rep told me that with the move to Big Sur, the only way to use, for example, a MacBook Air (2020), MacBook Pro (2018), or iMac (2019) as an external monitor is to purchase an external monitor combined with the use of Apple TV. iPads can serve as a tiny external monitor via Sidecar, but otherwise one is out of luck.

Same issue with MBP 16“ and Benq 4k 32“ monitor an Wacom Cintiq 22“. Trying to switch off/on and switching the ports. Now it works again. But hopefully Apple fix that issue asap!!

Roger from Germany

On your monitor, you should have the ability to toggle input options. On BenQ PD2700U, it's under System > DisplayPort (but on the PD2700U, it's only 1.1 and 1.4 options available). Hope that helps!

11.2.1 does not save anything for ultra wide 5k monitor. The mac resolution for my MSI PSI34WU is 3440x1440 at 60Hz. That is what I had before. Any resolution above this will give me a pixelated monitor.

There's one things that seems to be fixed in 11.5. Before 11.5 turning-off the screen (BenQ SW320) would require a restart of my MBP to get it detected again, now it seems it is detected! At least I can turn-off the screen and use the energy saving again.

The BLE with Apple Magic TracPad is slightly better, but still unusable...

And you just don't want to unplug the screen, that still leads to a crash. So the only way to "undock" is a full shutdown.

I had a somewhat similar situation, only my external monitor (29" Apple Cinema Display) would reduce the resolution to a much lower one - all on its own. After a lot of trial and error, I found if I unplug the Cinema Display and unplug the adapter (converting Mini-Display to Thunderbolt), wait about ten seconds, then plug in the monitor first, then plug in the adapter, it resets to the higher resolution it was previously set to.

I was thinking it was the adapter, but with everyone else's issues they are having, maybe it is just the OS software. Anyway, this methodology might help some of you. Good luck and take care,

Jim

I recently got a 2019 Macbook Pro and my external Cintiq no longer works (displays for about 10 seconds, then flashes on and off every few seconds). I thought it was Big Sur problem because my 2016 Macbook Pro with Catalina works fine.

I tried numerous different USB-C to DVI converters with no change in behavior. Finally, I rolled my 2019 back to Catalina and still have the exact same issue. So it would seems it's not a OS issue but a hardware issue.

This is so frustrating. I got this new laptop to be *more* productive and all I've done is chase this issue.

Also just updated to 11.5.2. But there is no change that my problems should have been solved.

I am on a 2020 MBP M1 and still running my external HDMI connected 34“ MSI monitor (via Anker USB-C hub) with 30Hz by 3440x1440 and bluetooth mouse stutters. No issues or whatsoever if I connect the USB-C hub to my windows laptop! It runs out of the box with proper 60Hz and no stuttering.

Sorry to dredge this back up, did you ever get this set up working. Just got the same dock (Targus Dock180EUZ) and am having same issue.

dock is recognised in system settings>USB and charges my M1 MacBook, but my screen isn’t recognised at all. (Connected via hdmi - hdmi to DVI adaptor…..)

should also add the monitor works when plugged directly in the MacBook with the same cables.