Users Report External Monitor Issues After Updating to macOS Monterey 12.3

Following the latest macOS Monterey 12.3 update, users are reporting several problems when using external monitors, ranging from Macs not detecting displays at all to inaccurate screen output, according to posts on the Apple Support and MacRumors forums.

24 inch imac and macbook monterey
In the ten days since the update became available to the public, users have already reported issues with the update bricking Macs that have had logic board replacements and problems with using game controllers. Adding to the list of issues, users are now reporting that the update is causing problems with external monitors.

According to users on the Apple Support and MacRumors forums, some external displays connected over USB-C are no longer detected by Macs after updating to the latest macOS update. As one user on Apple Support reports:

After updating my Mac mini today to 12.3, my monitor now no longer displays an image via USB-C, just keeps saying on no signal on the monitor.

I have tried HDMI and same issue. The odd occasion it will display a picture but once I shutdown or restart the mac mini it does not display a picture. The mac is booting up. I have had to resort to connecting it to my old TV with HDMI connection.

This is so frustrating.

Other users have shared similar experiences. While many also report issues with USB-C displays, others also say that HDMI connections to the Mac are not being recognized. Some users have been able to crowdsource potential workarounds in the meantime. According to one user on the MacRumors Forums, the issue stems from macOS not recognizing a DisplayPort protocol version, which meant they had to change the version to an earlier one with poorer quality output.

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.

Another short-term fix floated on both the Apple Support and MacRumors forums is to unplug the external display for a short time, plug it back into the Mac, and then plug the display back into a power outlet, after which it should work. Some users have also reported problems when using two external monitors with their Mac.

The issue of only one external display being recognized when two are connected to a Mac seems to have been present throughout the beta testing period for macOS 12.3. Even after release, however, the issue remains. As one user on the Apple Support forums relates:

2018 Mac Book Pro 15" and I have 2 external monitors (same viewsonic model), have been using fine for just under 2 years. After updating to 12.3, one is recognized and one is not and I have no clue why. I have swapped cables, connected other devices, including a iPad Pro (all fine) I have tried all 4 ports on the machine no difference. The Mac book flashes when the unrecognized monitor is plugged in, but never displays an image. the monitor seems to think it's connected (I don't get the no signal warning) nothing.... 8* the monitor is powered and the screen it bright (bleed from the backlight). The other monitor (same exact model) connects and works fine.

The online reports suggest that these issues are not arising when using Apple's new Studio Display, but instead with third-party monitors, such as those offered by BenQ and LG.

macOS 12.3 is Monterey's largest point-update since launch, bringing with it Universal Control along with several other new feature additions. MacRumors earlier this week reached out to Apple for comment on the issues users are experiencing so far with the latest macOS update. We'll update this post if we receive a response.

Related Forum: macOS Monterey

Top Rated Comments

UltimateSyn Avatar
25 months ago
Only Studio Displays are allowed from here on out. ;)
Score: 39 Votes (Like | Disagree)
kalsta Avatar
25 months ago
Because Apple makes both the hardware and the software, they are uniquely placed to offer this kind of user experience.
Score: 22 Votes (Like | Disagree)
TechRunner Avatar
25 months ago
I keep thinking I need to upgrade to Monterey, and Apple keeps giving me reasons not to.
Score: 18 Votes (Like | Disagree)
Freeangel1 Avatar
25 months ago
I might just go back to Big Sur. Monterey is like the Windows Vista.

Mac Studio owners are probably stuck on 12.3

Intel Macs can go back or even run 2 different versions of macOS.

Thats what scares me about the future of macOS on Apple Silicon.

You Cant Go Back. sort of like iPadOS.
Score: 16 Votes (Like | Disagree)
mxrider88 Avatar
25 months ago
New bugs, who would have thought..

My god macOS turned into an unpleasant mess.
Score: 15 Votes (Like | Disagree)
RedTheReader Avatar
25 months ago
More bugs on Monterey 12.3?!

Score: 10 Votes (Like | Disagree)

Popular Stories

Apple car wheel icon feature yellow

Apple Cancels Electric Car Project

Tuesday February 27, 2024 11:05 am PST by
Apple has canceled all plans to release an autonomous, electric vehicle, reports Bloomberg. Apple has been working on an Apple Car for more than a decade and invested millions of dollars into development before deciding it was not a viable project. Apple's Chief Operating Officer Jeff Williams today told approximately 2,000 employees working on the Apple Car that the project was canceled,...
Beyond iPhone 13 Better Blue Face ID Single Camera Hole

Six Reasons to Wait for Next Year's iPhone 17

Thursday February 22, 2024 4:20 am PST by
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models concurrently, which is why we sometimes get rumored feature leaks so far ahead of launch. The iPhone 17 series is no different, and already we have some idea of what to expect from Apple's 2025 smartphone lineup. If you plan to skip...
General Apps Messages

iOS 17.4 to Add This 'Groundbreaking' New Messaging Feature

Friday February 23, 2024 5:05 am PST by
With iOS 17.4, set to arrive in March 2024, Apple is bringing a new cryptographic security feature to iMessage called PQ3. This "groundbreaking" and "state-of-the-art" protocol provides "extensive defenses against even highly sophisticated quantum attacks," according to Apple. Let's break down what that means. Apple's iMessage service already supports end-to-end encryption, but security...
iOS 18 Mock iPhone 16 Feature Gray

iOS 18 Rumored to Be Compatible With These iPhone Models

Tuesday February 27, 2024 6:31 am PST by
iOS 18 will be compatible with the iPhone XR, and thereby also the iPhone XS and iPhone XS Max models with the same A12 Bionic chip, according to a post on X today from a private account with a proven track record of sharing build numbers for upcoming iOS updates. The post was spotted by MacRumors contributor Aaron Perris, and it has since been deleted. However, this was likely because the...
iOS 17

iOS 17.4 Coming Soon With These New Features for Your iPhone

Monday February 26, 2024 6:08 am PST by
In a press release last month, Apple confirmed that iOS 17.4 will be released in March, and the update includes several new features and changes for the iPhone. Key new features in iOS 17.4 include major App Store changes in the EU, Apple Podcasts transcripts, and an iMessage security upgrade. The update also adds new emoji and includes preparations for the launch of next-generation CarPlay...
applearcade

Game Developers Describe 'Smell of Death' Around Apple Arcade

Monday February 26, 2024 7:24 am PST by
Some game developers are dissatisfied with Apple Arcade amid concerns about the subscription service's future, a new report claims. Sources speaking to mobilegamer.biz described a "smell of death" around Apple's games subscription service and noted the difference between the company's investment in TV and music, and its interest in games. "At the very top of the company there needs to be a ...