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george22

macrumors newbie
Oct 26, 2007
14
4
Thanks.. I'll give that a shot if it is an option on my monitors. What is odd is that one still works with USB-C.. but maybe only one at a time with 12.3 using v1.4.
 

danimir

macrumors newbie
Dec 27, 2007
10
13
Same here. I have 2 monitors connected via USB-C, with DisplayPortVersion 1.4 only one of them was working at the time after OS X 12.3 update. As soon as I've downgraded DisplayPortVersion on both monitors to 1.2, both monitors started working fine like a charm. I've also reported this to Apple using developer feedback app. Hopefully they'll fix it.
 

Station Grey

macrumors member
Jun 18, 2020
50
73
I've solved this problem (on 2022-03-15). On my monitor (LG LCD 27 27UN880-B IPS) I've went into settings, and I've lowered the DisplayPortVersion from the default v1.4 to v1.2. As soon as I've lowered the monitor's DisplayPortVersion, my Mac with OS X 12.3 has started recognizing the second display correctly. It seems that the new OS X update has issues with a DisplayPortVersion 1.4 protocol (has faster data rate, faster refresh, and stream compression). Hope this helps.
Thanks. That got me excited but my cheapo Chinese monitors from Amazon don't have such a setting, sadly.
 

george22

macrumors newbie
Oct 26, 2007
14
4
Well, crap. My ASUS monitors only appear to do DisplayPortVersion v1.1 and v1.2 (default). The menu is a bear to navigate but I'm still going to mess with the settings and report back.
 

george22

macrumors newbie
Oct 26, 2007
14
4
OK - I have success changing my ASUS from v1.2 to v1.1. Both monitors are working again with USB-C.

Thanks @danimir for the tip!
 

iGeneo

macrumors demi-god
Original poster
Jul 3, 2010
1,068
1,991
I've solved this problem (on 2022-03-15). On my monitor (LG LCD 27 27UN880-B IPS) I've went into settings, and I've lowered the DisplayPortVersion from the default v1.4 to v1.2. As soon as I've lowered the monitor's DisplayPortVersion, my Mac with OS X 12.3 has started recognizing the second display correctly. It seems that the new OS X update has issues with a DisplayPortVersion 1.4 protocol (has faster data rate, faster refresh, and stream compression). Hope this helps.
Good catch! ?
 

miller1952

macrumors newbie
Mar 14, 2021
5
1
Anybody seen this?

2nd display is connected to HDMI and it will not work? Happened on reboot after beta install
I have a mac mini. three monitors worked before 12.3, now just two work. The HDMI works, only one of the thunderbird connected monitors works. Do they actually test anything before shipping it?
 
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mgsxx

macrumors newbie
Mar 15, 2022
1
0
I've solved this problem (on 2022-03-15). On my monitor (LG LCD 27 27UN880-B IPS) I've went into settings, and I've lowered the DisplayPortVersion from the default v1.4 to v1.2. As soon as I've lowered the monitor's DisplayPortVersion, my Mac with OS X 12.3 has started recognizing the second display correctly. It seems that the new OS X update has issues with a DisplayPortVersion 1.4 protocol (has faster data rate, faster refresh, and stream compression). Hope this helps.
THANK YOU.
This helped me.
 

99-Turbo

macrumors newbie
Jun 24, 2010
7
0
Minneapolis
Same here. I have 2 monitors connected via USB-C, with DisplayPortVersion 1.4 only one of them was working at the time after OS X 12.3 update. As soon as I've downgraded DisplayPortVersion on both monitors to 1.2, both monitors started working fine like a charm. I've also reported this to Apple using developer feedback app. Hopefully they'll fix it.
Thank you as well, I had the same problem (Mac Mini 2018). I had two monitors on DP; one is maxxed at DisplayPortVersion 1.2, the other was 1.4. I downgraded and all was working again.

What an annoying bug.
 

andrewsyd

macrumors newbie
May 10, 2012
11
1
Ok my situation has been a little different -- just posting this in case it helps out anyone else.
I have a 2019 MacBook Pro 16 inch and BenQ PD3220U Monitor connected via Thunderbolt. Upgrading to Monterey 12.3 overnight broke the connection between the monitor and the MacBook Pro. Tried to access the monitor's settings but actually couldn't bring up the menu without the monitor having a signal to a device (what the??) so I had to grab my (not-yet-updated) Mac mini from another room and plug that in. Ugh.
Anyway I finally got into the monitor DisplayPort settings to switch from 1.4 to either 1.1 or 1.2 as suggested but noticed it was already on 1.2. Turns out I had changed it in Dec 2020 due to a similar problem after a macOS update.
So I changed DisplayPort to 1.4 and that allowed it to connect to the MacBook Pro again. Phew! ?
 

aziatiklover

macrumors 68030
Jul 12, 2011
2,701
146
8.8.8.8 and 8.8.4.4
I've solved this problem (on 2022-03-15). On my monitor (LG LCD 27 27UN880-B IPS) I've went into settings, and I've lowered the DisplayPortVersion from the default v1.4 to v1.2. As soon as I've lowered the monitor's DisplayPortVersion, my Mac with OS X 12.3 has started recognizing the second display correctly. It seems that the new OS X update has issues with a DisplayPortVersion 1.4 protocol (has faster data rate, faster refresh, and stream compression). Hope this helps.
OMG! It works for me. Lowered to DP v1.2 on my 27" LG HDR and it worked. However, HDR is disabled. My other LG monitor is still on v1.4 and still works since it wouldn't let me downgrade. Thanks for the tips.
 
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748s

macrumors 6502a
Dec 14, 2001
692
31
Tiger Bay
Mac mini (6 core i5) with LG 32UL950 (display port V1.1), thunderbolt connection.
Monitor no longer works with thunderbolt connection after 12.3 update.
Monitor works with HDMI connection.
Thunderbolt cable tested on other thunderbolt devices, cable OK.

update.......
Disconnected display from power for 10 minutes, now thunderbolt connection working.
Odd.
 
Last edited:

jjayr41

macrumors member
Sep 22, 2016
94
52
I did the same thing that 748s did, I shut down my 14" M1Pro MacBook Pro and unplugged my LG 32UP550-W overnight. This morning, plugged in the usbc and powered on my Mac, and the monitor works??? Though the display settings were reset as the backgrounds had different backgrounds compared to before the OS update. its working for now though.
 

cobra521

macrumors 6502
Dec 14, 2016
305
102
FL
Aaaargh!

My second monitor went away, similar to lots of folks' PCs above, with the "upgrade" to Monterey 12.3 (not beta!). I have a Mac Pro 7,1 with two Apple video cards (W5700X MPX), primary display NEC PA301W and HP Z32 second display.

The symptom was "no input detected" on the second display. At first I thought the second display's cable had become defective or unplugged but that turned out to be incorrect.

I fixed it but not sure how :rolleyes:

My approach (aka Monkeys and Typewriters) was to keep moving the USB-C connector to different sockets on the video cards until it finally resulted in input to the second monitor. I use the Displayport input to the Z32 with a USB-C to Displayport cable adapter on the PC end.

I rebooted the PC and the monitor several times each during the process.

I wonder if there's a way to optimize the connection of two monitors with the 2 x W5700X MPX setup?

Really annoying, Apple...

Tom
 
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horrbort

macrumors newbie
Mar 16, 2022
3
0
Having same problem with full release 12.3 now, got update pushed to me today.

MacMini 2018 intel based, LG HDR 27UK850 * 2 both connected via USB-C

Only detects one screen at a time, whichever comes up first.

Did anyone figure out a way to downgrade the OS? Apple Support is no help. TimeMachine on a network drive only offers data migration and not restoring full disk so thats no help at all. Maybe there os a new beta with the problem fixed?
 

SaguaroSeven

macrumors 6502
May 20, 2020
263
108
Washington DC
Agree setting DPI to v1.2 improves situation. Found this looking for solutions to display wonkiness on Mac mini 2018 with one display, an LG 35WN65C ultrawide. After install, everything seemed ok, but later display would not get video after wake from sleep. Tried HDMI connection, but didn't support ultra-wide at desired resolution. Eventually, I tried DP setting on display and surprisingly all seems ok.

What was Apple trying to fix display-wise? Monterey 12.3 seems good otherwise; iOS 15.4 is another story (lots of headaches with AirPlay to HomePods + other speakers.)
 

andrewket

macrumors regular
Dec 14, 2012
134
10
Sigh, same problem here. Updated to 12.3 and my second monitor stopped working.

I'm using two LG 4K displays connected via Thunderbolt/DisplayPort on a Mac mini 2018. Both monitors work as long as it is the only one plugged in. How the heck does stuff like this slip through the beta? UGH.
 

andreobrown

macrumors newbie
Apr 13, 2013
2
1
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.

This worked for me. The system ended up seeing 3 monitors, one of which had a weird resolution. WTH?! It also continued to work when I plugged the HDMI cable out of the Mac Mini, leaving the DP cable in. However, this did not survive a restart.

I've solved this problem (on 2022-03-15). On my monitor (LG LCD 27 27UN880-B IPS) I've went into settings, and I've lowered the DisplayPortVersion from the default v1.4 to v1.2. As soon as I've lowered the monitor's DisplayPortVersion, my Mac with OS X 12.3 has started recognizing the second display correctly. It seems that the new OS X update has issues with a DisplayPortVersion 1.4 protocol (has faster data rate, faster refresh, and stream compression). Hope this helps.

This solved it for me. Thanks!
 

horrbort

macrumors newbie
Mar 16, 2022
3
0
Nothing worked for me, I had to revert back to 12.2.1 and that wasn't easy either. If anyone is wondering here's how:

1. Download 12.2.1 from Apple CDN here: InstallAssistant.pkg and create install media
2. Boot into recovery mode. Restoring from TimeMachine doesn't work for OS anymore. Utilities->Secure boot-> Disable everything
3. Boot to bootable flash, wipe internal HDD otherwise won't install, then install 12.2.1
4. Run "Migration assistant" to restore TM "image"

This little update just costed me 1.5 days of work. I'm permanently disabling updates. Will only jump major releases.

Good luck everyone.
 
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crwth

macrumors newbie
Oct 14, 2011
21
6
what a mess, on my samsung monitors DisplayPort Ver is dimmed, so i can't access it to see if there is a 1.2, 1.4 choice available.
 

daholby

macrumors newbie
Jan 24, 2020
7
2
I'm literally selling a MacBook for one of my employees and buying him a windows machine.
He's a presenter and used to connect 2 monitors to his computer and now only one will work. I can't spend 1.5 days to revert. Done with Apple. (BTW this is the second time an update broke display issues. the last time this happened was in 2020 and it took SIX MONTHS to get an update that fixed the issue. I would link the last thread but macrumors deleted it)

Apple is not worth the price anymore. The 3 windows machines we have at work are outlasting all our macs while being cheaper and easier to repair.
 
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