12.3.1 also didn't solve the issue for me.
portram
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Hello everyone,
I had similar issues and recognized that it might be related to the DisplayPort Alt Mode. I came across this because because MonitorControl (https://github.com/MonitorControl/MonitorControl) only works with native DDC (protocol to control backgroundlighting, sound, etc. on monitors) with cables and adapters that use DisplayPort Alt Mode.
I have three different cables / connectors that I tried over the time (from May 2021 when I I got my M1 MBA to now) with my Dell S2712QS. My goal was to get 4K@60 Hz with native working DDC working all the same time. I also tried USB-C to DisplayPort adapters but unfortunately my Dell doesn't like 4K@60 Hz over DisplayPort (https://www.dell.com/community/Monitors/S2721QS-black-screen-for-1-2-seconds-random-5/td-p/7908482) , so I pivoted to HDMI.
Here are my results:
i-tec C31VGAHDMIADA + some random HDMI cable
4K @ 30 Hz, DDC works => uses DisplayPort Alt Mode
The monitor doesn't get recognized in 3 out of 4 times (after my Mac goes to sleep / I plug the monitor in). Unplugging and plugging it back in several times usually does the trick.
Delock (84905) USB-C to HDMI cable (https://www.delock.de/produkte/G_84905/merkmale.html?setLanguage=en)
4K @ 60 Hz, DDC works (uses DisplayPort Alt Mode as advertised)
It worked about two times for me, right when I got the cable and checked 4K@60Hz + DDC and then after unplugging and plugging it back in I never really got it to work again.
I just got this cable today and in the process of trying to find out why, I go to know that so may other people have display issues on their M1 Macs as well
Inline 64112 USB-C to HDMI cable
4K @ 60 Hz, DDC doesn't work
On their website (https://www.inline-info.com/en/products/cable/usb-to-display/10680/inline-usb-display-cable-usb-type-c-male-to-hdmi-male-dp-alt-mode-4k2k-black-2m) they state the cable uses DisplayPort Alt Mode but DDC doesn't work with it. I don't know what to make of this other than that it seems to be working now and maybe their implementation or claim of DisplayPort Alt Mode is wrong.
I hope somebody finds this useful.
Cheers