Monterey 12.3 Beta broke second display?

[gdbleb]

Downleveling DP on a newer Dell monitor from 1.4 to 1.1a worked for me as well. Didn't even know I could do this. Definitely a bug.

 

[sfotony]

Adding my info in cases others are in the same boat. I'm seeing the same one a 2019 MBP 16 and a Samsung CRG9; I normally use a Caldigit TS3+ in between the two. So far, these combos do not work:

I’ve tried:

• MBP TB3 -> caldigit -> DP1.2 CRG9
• MBP USB3 -> Apple HDMI Adapter -> HDMI CRG9 (works but the screen is pink; getting a better quality HDMI cable to retry)
• MBP USB3 -> Belinda USB3 to mini-DSP adapter -> DP1.2 CRG9
• MBP USB3 -> DP1.2 CRG9

I was already running on DP 1.2 as this machine had issues waking the screen (my previous 15 MBP from 2017 had no issues waking on DP 1.4). DP 1.1 doesn't seem to work either. I have an 8k HDMI cable (to use with the Apple HDMI Adapter) and a DP to HDMI cable (to use with the Caldigit) on order to try this weekend. Will update if either of those actually work.

 

[iEnvy]

Yup, DP1.3 over Thunderbolt/USB-C fixed black screen issue but I'm still not getting full 4K resolution.

 

[BuaaLzd]

got the same issue. I make one of the monitor link to the Mac mini with dp and hdmi at the same time, and the other monitor through dp. then the two monitor works. so confusing.

thanks man, it works for me. I tried the DP version downgrading method, but nothing happened. then I follow your solution, it shows the systems detect 3 displays, 2 of which are from exactly the same monitor, then I unplug the HDMI, both monitors can still work.

 

[piter75]

I have a DIY 21.5" screen (based on the iMac 21.5 4K) and it also stopped working with macOS 12.3
It supports max DP 1.2 and setting it to DP 1.1 did not help either.

The interesting tidbit though is that it stopped working with MBP 16 2019 (Intel) but it still works with MBP 13 2020 (M1). Both machines are upgraded to 12.3.

Is it a "gentle" nag from Apple with the message "It's time to move on"?

 

[andrewket]

I opened up a support case with Apple. I don't think they will resolve it soon, but at least this way I know they're aware. I doubt they watch these forums. Downgrading my monitors from 1.2 to 1.1 didn't help.

 

[horrbort]

I tried resolving it via Apple Support, they are clueless. They told me it's impossible to downgrade to 12.2.1 and to either try a different cable to roll back to MacOS 11. I don't think it will accomplish anything. You know how it is - if it's not Apple Pro Display™ they don't care

 

[sbraidley]

Having the same issue with 12.3, with a 2018 Mac mini with the Samsung Odyssey G9. Connected by USB-C to DisplayPort 1.4 cable, I found that also connecting a HDMI cable to the Mac following boot up fixes the issue and then can be removed, not ideal but a workaround until Apple fix this.

 

[ryan.davis]

I have a 2016 MacBook Pro with a 27 in LG Ultrafine and am having issues connecting since the upgrade too. Where exactly do you access the settings to change the display port version to 1.2?

 

[ralphthemagi]

I have a 2016 MacBook Pro with a 27 in LG Ultrafine and am having issues connecting since the upgrade too. Where exactly do you access the settings to change the display port version to 1.2?

That's the fun part about the UltraFine—you don't. It has no settings whatsoever.

The only thing you can do with the UltraFine is "factory reset" or "Upgrade Firmware" through the LG Screen Manager. But there's a good chance the screen manager won't work, and neither of those two things really do anything anyway. There was a bug with volume that was fixed with a firmware update years ago about that's honestly it.

 

[marteeny]

I have the Studio Display, Thunderbolt displays, and the Cinema display... this issue only affecting the thunderbolt & cinema displays. Since apple's monitors lack the ability to revert to display port version 1.2, the best workaround i've found is to just have the displays that suffer on a power switch that I click off for 15 minutes - usually while I go make coffee or whatever. When I come back, I toggle the power switch back on and they seem to work again. Hope this helps someone.