Mac Mini (M1) dual display doesn't work.

I think it’s wonderful that you documented all of this. I was on the phone with Apple for about two hours today. I think with Covid and the holidays most people are starting to get their machines and find these problems and report them. I have a follow up call on Monday with the senior advisor who is going to relay all the information to the engineers

The thing to keep in mind, Lars.de, is that Apple isn’t here. So the likelihood that they will «find this thread» is minimal.

The best is to use Apple support, as you have done (though you could refer them to «this thread»), or use Apple’s Feedback webpages.

Thanks Halliday.

Following your information I have reported this as a bug via the Apple Feedback website for Mac mini.

I provided them the link to this thread as well and pointed them to the video that taro0922 posted.

After several tests with Apple Support (clean install,...) they decided to gather information and logs from my Mac mini. I sent them the files for internal investigation with their engineers. They should contact me under 72h. I hope they finally find what's wrong...

I tried using two USB-C to Mini-Display Port adapters (I have two 24" Apple Cinema Displays) and this did not work either. Originally I only tried one using USB-C to MDP along with the HDMI adapter but I just tried to restart with both monitors plugged into USB-C port and only one worked. When I unplugged the working one the non-working monitor would then light up and work.

I've also used the following connections with no solution:

USB-C to USB-C

USB-C to HDMI

USB-C to Displayport

All cables are cabable of 4K 60fps. If I connect my MacBook Pro to them, I have no problems at all. I had a few unsuccessful chats with Apple and reinstalled MacOS Big Sur with no result. I really hope that they fix this with a software update. Changing the display settings just helps temporarily.

Let us know if that adapter solves anything. In Canada that's like a $100. I don't want to waste that kind of money on an adapter unless it solves the problem (which at this point I don't think it will, to be honest).

But to be clear: it does technically function. I can use both displays for hours with no problems. The only issue is when waking up the Mac or turning it on. I always have to change a thing in the display settings to detect the displays again properly. I’m sure it has to be a bug. Apple also said multiple times that it should work.

Now I installed the newest MacOS Big Sur Beta and nothing has changed. I’ve reported this problem to Apple. I’m staying on the beta profile and let you guys know, if something has changed with an upcoming beta update.

Unfortunately not. I have two BenQ EW3270U which have HDMI Ports, a Dispaly Port and a USB-C Port. None of these ports solve the issue for me. @Sputnixk gave me some hope for a USB-C to mini DP connection, so I ordered a Adapter on Amazon. I will try to use this adapter with a mini DP to DP cable tomorrow. What a mess.

I'm using a standard HDMI cable for one monitor and this cable for the other: https://www.amazon.co.uk/gp/product/B08D6LFJXB/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

These are the monitors I am using: https://www.amazon.co.uk/gp/product/B073NTCT4Q/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1

For the Mac Mini>HDMI cable>LG:22in , I am using a random HDMI cable I've been using long time. It's not an original one. It doesn't even show any brand name so I don't know what it is.

I don't think the new monitor fixed the issue, so it must be the new cable(j5create) or the fact that I am not using an adapter anymore. Once I receive a USBC-to-Displayport cable from Amazon I can try different combinations in an attempt to isolate the issue.

I will keep everyone posted on this.

That's good news, guys. It looks like some adapters or cables may solve the issues. Keep up posted kimac with that cable. I'm going to try a few and see what happens. My first order is going to be an adapter from eBay (USB C to DP), but it is going to take a few weeks to arrive.

Yes, Sputnixk. I think that's one of the issues. The adapter I bought is DP1.4 8K. I think that could work. Maybe not. But it is time for me to try different things. The USB C to HDMI cables and adapters I tried so far didn't work for me. If this DP adapter doesn't work, I'll try the cables that worked for the other guys. Thanks everybody for the input.

Sorry to be redundant but the only problem with the adapter or cable argument for me is that it doesn’t matter in the end. I can make everything work great when I refresh my refresh rates. It’s just frustrating that it has to be every time I restart or wake.