Big Sur 11.1 External Display Issues!

What's so difficult??

Each time after waking up from sleep I have to resize the windows which where opened for my M1 Mac mini.

The state in which the windows on the screen come alive is 16:9 instead of the 16:10 resolution of the monitor. It doesn't matter if it's Safari, Apple software, or some other software from non Apple developer.

The monitor (Dell Ultrasharp 2415) is connected using HDMI.

Using Catalina on a Intel based Mac Mini this wasn't a problem...

What to do?

Big Sur 11.2 didn't solve this resolution issue...

Yesterday my new monitor was delivered. A LG 32UN880 ergo. It is hooked via DP to a link-up “apple certified “ (not sure what It does mean) thunderbolt 3 docking station. Surprise: it works at native 4K res at 60Hz. I connected also an XP PEN innovator 16 tablet display and had no issues so far (but it’s just one day).

however, no way to connect the monitor to the USB-C port of the docking, it is no seen by the system. Only if I connect it to the thunderbolt port is recognised. It could be normal, Maybe the usb-c port of the docking is only used for data other than video signals.

by the way, a little too many cables, but displays are running just fine so far, but I do believe that big sur has a problem in detecting certain types or usb-c peripherals

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!

Its not just 16inch MBP.

I have a new 13 inch M1 MBP. I brought a BenQ 32inch monitor PD3220U with Thunderbolt 3 and I cannot even use it. The monitor works find with my Dell work computer. I haven't tried any of these workarounds yet. I guess I'll go get an HDMI cord and see if that works for now.

I have the same issue now on my 16" MBP with a BenQ PD2720U monitor. Everything went wrong once I updated and then reconnected the laptop to the screen. My work 13" MBP with Catalina has absolutely no issues.

Thanks to everyone that suggested switching in the monitor menu "System - Advanced - DisplayPort - 1.4 to 1.2", this fixed the issue for now, but only when I connect with the Thunderbolt 3 cable. HDMI (both Apple display adapter and a USB-C hub) is still messed up showing a full 4K non scaled resolution.

Just updated to Big Sur 11.2.1.

NOTHING HAS CHANGED!!!

Mac Mini now in repair shop trying to recover data because it refuses to recognise monitor.

MacBook Pro only recognises Monitor after multi attempts (no rhyme or reason here) to disconnect/reconnect.

VERY SLOPPY MR COOK!

[Edited by Moderator]

11.2.1 beta and 11.3 beta did not fix the issue for me when I tried them a few days ago. I have not tried the final release as I've had to downgrade to Catalina 10.15.7 in order to get any work done.

2019/2020 Macbook Pro 16"

Monitor is LG32UD99-W connected via USB-C

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.

I got a UPERFECT Portable USB C Monitor, 15.6 Inch Portable Monitor IPS Screen 1920 x 1080 Full HD with USB-C Type Connector.

It did not activate anymore over USB-C on MacBook Air M1 and old MacBook Pro 13", have to use HDMI

Also DDC did not work on my big curved DELL screen.

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.

Can anyone with the LG 32UD99 4K monitor confirm that changing settings from 1.4 to 1.2 gets us 4K 60 back? I'd normally not care about updating until fixed but now I'm being forced to decide on if I want to be up to date with security patches or have a working monitor... :(

The LG 32UD99 uses DisplayPort 1.2 only from what I have read. I have been using a USB-C Cable to HDMI as a patch until Apple can get off their a*&$s and issue the fix. The resolution is OK but my dual (32UD99) monitors randomly blackout for a second frequently. It's a patch "bandaid" for now so I can get work done. This issue is going on 60 days!

@Innov8motor

The LG 32UD99 does have the option to switch from 1.4 to 1.2. Does it only utilize 1.2 even if 1.4 is set? I'd just use an HDMI cable but everything I use is routed via a powered USB hub to the monitor then all I do is plug a single USB C to whatever machine I intend on using. With a usb to hdmi I'd have to fiddle with the hub, etc, No thanks Apple.

PS. Thanks for clarifying and saving me the trouble.

If anything, I think 11.2.1 is even worse. I would have to do the whole powering off, unplugging everything, then powering on again once every 5 days or so. Now it doesn't even last a day.

Getting so tempted to just restore the backup I did before I upgraded.

Same issue here, MBP 16" 2019 with 4K LG 32UD99 connected directly via USB-C.

No problems using 10.15 Catalina, but with the new Big Sur, the screen isn't recognized and i have a hard time getting it to display 4K resolution. Om now on Big Sur 11.2.1.

Probably the Big Sur update messed with the T2/CD3215 chip, as the Catalina update did for some users corrupting their chip leaving them with a non charging computer.

Only solution i've found is to restart the screen until it displays the correct resolution, which sometimes takes 20-30 restarts.