MacBook Pro 16'' with M1 pro flickering with my 4k BenQ EW3270U USB-C monitor with display refresh rate at 60 Hertz

We purchased a handful of 16inch and 14inch M1 MBP's. We have been pairing them with three different 4k monitors. HP, LG non HDR, LG HDR. The HP and LG non HDR have very little flicker or vertical lines but the LG HDR has been a mess. Keep in mind, we had previous generation MBP's connected with all the same cables and monitors with no issues and many of us also have Windows laptops or desktops for different kinds connected to these same monitors / different inputs with no issues.

The LG HDR monitors flicker like crazy unless we turn HDR in Display Settings on the MBP for the external display. As soon as we do that, no flicker from the MBP's with the LG HDR monitors.

We have tried MANY different USB-C to Display and USB-C to HDMI all with the same results. HDMI to HDMI we haven't seen the issue but we also have been focused on USB-C cables since we had so many from our 2020 Macbook's and all our employees use dual monitors in addition to the laptop screens.

I'm old school and play Startcraft 2 on the M1 MBP. When playing on the LG HDR external display without HDR enabled Starcraft flickers allot and it has the vertical lines. Certain menus within the game cause it as well. In Monterey, when we move windows around or off the screen we can reproduce the same issues. The problem seems to be lighting, shading or certain textures.

Fortunately with so much equipment to test dozens of scenarios were able to find some solutions but Apple really needs to fix this. We have seen no improvements change display rates or monitor settings or factory resetting monitors etc. We really tired everything!

Hope this helps others who are seeing issues. Other than the external screen problems the new MBP's have been fantastic in every other way.

Tim

Flickering with screens that support variable refresh rate is a very common issue in Monterey, and of course it is not supposed to be like that. It looks like VRR support in Monterey is massively flawed. This flickering should not happen with a proper implementation of FreeSync / GSync support. Here are some links to other reports about the same issue:

https://forums.macrumors.com/threads/variable-refresh-rate-freesync-gsync-flicker.2320463/?post=30551784

https://www.reddit.com/r/MacOS/comments/qg9qki/updated_to_monterey_monitor_is_flickering_help/

Please file a bug report with Apple to make them aware of the problem and get the flickering fixed ASAP.

https://feedbackassistant.apple.com

Just to say I also fixed this problem by using an HDMI cable rather than the USB-C to DisplayPort cable.

I'm using a Dell S2721QS external display (capable of 4K at 60hz). I just got a new M1 Mac, running macOS Monterey and experienced this flickering problem for the first time. I was on a 2013 Intel MacBook Pro before, running Big Sur and never had this problem when connecting the display.

Experiencing the same issue with a Gigabyte M32Q USB-c monitor and MacBook Pro Max 16-inch. Flickering only occurs when connected via USB-C. HDMI connection is flicker free. I’ve used two different brands of cables so far with similar outcomes. Also experienced the flicker issue utilizing different Thunderbolt ports on the MacBook.

Just buy a 4K@60hz HDR HDMI 2.1 cable and end your display woes. If you do that, disable free sync. There is nothing in your 2017 MBP that is in the new 16-inch M1 Pro, so comparisons are out the window with the same display.

Have the same issue with my Macbook Air M1 -> CalDigit TS3 -> Dell S2721QS. Variable refresh rate in MacOS work on 40hz and not flicker but some software like chrome with youtube fullscreen mode or telegram with full screen photo preview made 60hz and flickering return. Tryed YPbPr instead RGB it help. I can work in 4k60hz but I don't know how force YPbPr, MacOS and monitor return to RGB after lock screen.

This isn’t a solution, and doesn’t help those of us with multi-monitor setups using displayport. But yeah, using HDMI does work (i also want to note that the HDMI port on these computers is not 2.1)

I was also able to fix this by using an HDMI instead of DisplayPort to USB-C 3. Not really a fix though as I am using a docking station that doesn't have an HDMI port and needing to plug in an additional HDMI every time is not ideal.

Found some solution for dell s2721qs. Turn on monitor smart hdr in desktop mode, turn on on mac hdr in settings then turn off. Now I have stable 4k60hz rgb with turn off hdr on mac. Don't know how long it will be work, tried lock screen work fine after. Also turn on fast wake up on my monitor.

Hello geek_42,

Thanks for reaching out through the Apple Support Communities about that behavior when using your external monitor with your new MacBook Pro.

Have you had the opportunity to test your new MacBook Pro with any other external monitors?

How about testing with another USB-C cable?

Does this occur with all the Thunderbolt 4 ports on your new MacBook Pro?

Hopefully those details will help to further isolate this behavior.

Take care.

I’m having this issue. I’musing my Xiaomi Mi 27 inch external monitor using HDMI and I experienced flickering and linear lines. But on my MB 2019 16” i9, I don’t problem with it. Only on my M1 Max. I think the problem is the GPU of M1 chips. Apple needs to fix this issue.

I am also facing the same problem with Macbook Air M1 on Monterey.

The screen supports 4k @ 60 hz through usb-c -> DisplayPort. I had this setup for over a year with different macbooks on Bigsur and below and never had any issues. Only with the Macbook on Monterey.

It doesn't flicker, but the screen goes blank for a second or two and comes back when it's on 60hz. I am using Dell S2721QS

I have a similar problem on a MBP M1 Max, not exactly a flickering, but when I use my USB-C -> Displayport cable on the thunderbolt right above the magsafe, I just get a black screen (System > Displays) shows my monitor but no image is displayed.

If I change to the second left thunderbolt port it works with no problem, same with the right thunderbolt port.

To be clear, all thunderbolt ports work for charging and external devices, it's just for the external monitor that I'm having this issue with the first thunderbolt port from the left.