macOS 12.3 Monterey 4K Monitor Problems DisplayPort 1.4

LG 34UC98 W cuved monitor

macOS 12.3 may cause DisplayPort problems.

The update to macOS Monterey version 12.3 may have caused you problems if you connected a non-Apple monitor to a Mac mini, for example. Many use 4K monitors and it is possible that these (when booting) no longer display a picture or only one works even though you actually have a dual monitor setup.

The reason seems to be that Apple did not correctly implement the DisplayPort 1.4 standard in macOS 12.3. 4K monitors that rely on DisplayPort 1.4 are completely normal. The LG 49WL95C or the LG 27UL850-W could be mentioned.

LG 49WL95C, 27UL850-W and other 4K monitors under macOS 12.3

But there is a solution to the situation: using the DisplayPort standard 1.2. This is also fast enough for 4K monitors and continues to work under macOS. To use this trick you have to go through the menu in your monitor settings (in the monitor, not in macOS) where you can set the DisplayPort standard. Just set it to 1.2 here and everything should work fine like before updating to macOS 12.3

10 thoughts on “macOS 12.3 Monterey 4K Monitor Problems DisplayPort 1.4

  1. I’m impressed by how many bugs Apple has been introducing in MacOS in the last few years…

    This issue with the monitor is extremely annoying and deeply bothers my daily work;
    I think it was with the upgrade to Monterey last year that I lost completely the content of my SSD due to corrupted encryption after updater failed to validate needed space (basic error which required to factory reset);
    between other smaller or less impacting issues.

    1. Yes, it seems the basic functions sometimes take a big hit out of nowhere. It seems you had a good backup, otherwise have a look here before that problem arises again: Unfortunately, we tend to do the latest backup before an update now. Yes, we should have done that always, but we trusted macOS so much. But now we rather take the time to run another last backup before upgrading.

  2. Dell λͺ¨λ‹ˆν„°λ„ usb-c 포트둜 μ—°κ²°ν•˜κ³  λ“€μ–Όλͺ¨λ‹ˆν„° μ‚¬μš©μ‹œ λͺ¨λ‹ˆν„°μ— μžˆλŠ” usb μž₯μΉ˜λ“€ μ—°κ²° μ•ˆ λ©λ‹ˆλ‹€.

    1. Thanks for your feeback! πŸ™‚ I translated your comment for the other readers:

      “When a Dell monitor is also connected through a usb-c port and a dual monitor is used, the USB devices on the monitor cannot be connected.”

  3. Not working for Mac Studio and Odyssey G9. It only happens to NOT WORK with Monterey. Big Sur works pretty fine!

    1. Thanks for your feedback!

      Yes, it seems things change back and forth between different versions. As for the Mac Studio: how do you deal with it? That machine comes only with Monterey, so do you use another monitor?

  4. Hi there,

    thanks for the beautiful article. So far it didn’t helped. I am on Monterey 12.5.

    Also resetted the SMC NVRAM and so on. πŸ™

    When you say “Just set it to 1.2 here”:
    – Do I also have to set the usb-c to 1.2 in the monitor settings or keep that to 1.4 still?
    – I have a usb-c to DisplayPort 1.4 cable. Do I also need to buy a new 1.2 cable?

    Thanks a lot for your help!

    1. Hello Dieter,

      yes, set the monitor in its settings to 1.2, so the Mac sees it just as a 1.2 device. The cable should not be (but still can) be the problem.

      Also, the problem should be fixed under 12.5. If it still not works play as I said with the monitor settings and try another cable. Sometimes (believe it or not) just unplugging the monitor and reconnect works for us.


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