macOS Monterey 12.3 still causing external display issues

Mac Studio Lifestyle
Mac Studio Lifestyle (Image credit: Apple)

What you need to know

  • Users are reporting more troubles with macOS 12.3.
  • Some users are complaining that can no longer use USB-C external displays.
  • The update has already borked game controllers and some Macs with replaced logic boards.

Yet another major issue appears to have been spotted in the latest version of macOS Monterey, this time pertaining to external displays.

Reports noted by MacRumors indicate that some users are struggling to use external displays connected over USB-C. The issue has been a persistent problem in the 12.3 update even when it was in beta:

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One disgruntled user wrote:

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.

Users in the reply thread and over at MacRumors' forums appear to be having the same issue. One user suggested that this is an older DisplayPort bug on macOS Monterey that does have a workaround:

So this is related to a previous long-standing bug with DisplayPort, which forced all of us to go into our monitor settings and switch from DP1.4 to DP1.2 so our external monitors would work. Apparently in "fixing" this bug, Apple decided that checking autonegotiation was redundant and the user needs to manually fix things.The solution is to set your monitor to DP1.4. For a BenQ monitor, that is going to suck, because if you don't have a valid source input, it won't give you the display settings menu. You'll need to hook up a second computer to the monitor without macOS 12.3 so the monitor has a signal, then go into the menus (System -> Advanced -> DisplayPort) and switch back to DP 1.4. Your monitors will work.

It continues a rough release for macOS 12.3, following reports the new update is causing issues with various game controllers and was bricking Macs that had previously had their logic boards replaced.

Stephen Warwick
News Editor

Stephen Warwick has written about Apple for five years at iMore and previously elsewhere. He covers all of iMore's latest breaking news regarding all of Apple's products and services, both hardware and software. Stephen has interviewed industry experts in a range of fields including finance, litigation, security, and more. He also specializes in curating and reviewing audio hardware and has experience beyond journalism in sound engineering, production, and design.

Before becoming a writer Stephen studied Ancient History at University and also worked at Apple for more than two years. Stephen is also a host on the iMore show, a weekly podcast recorded live that discusses the latest in breaking Apple news, as well as featuring fun trivia about all things Apple. Follow him on Twitter @stephenwarwick9