Swap displays and they both work independently. Just setup a new Mac Mini w/M1 running 11.0.1 and when I plugin two display ports, the second one does not work.

This is definitely a Big Sur issue.I have a 27' iMac 5K with an external 43' LG Monitor running 11.0.1, iMac is running at 5K and the LG supports 4K HDR via USB-C (thunderbolt). I do have a have a CalDigit TS3 Plus at home which will fix the issue until they correct it.but you guys aren't 's an issue = not good Apple, hard to imagine how they missed this issue, given the Beta testers were reporting this back in June/July from what I see on the forums. Kind of shocked, being a long time Mac user without a lot of issues over the last 14 years.

Daisy chaining the 27' to the 43' worked, but with Mirror only option and lower 2540 res on the 43', which was what is 'supported' via the Dell specs. I was using a USB-C to Display port cable on the 43' and HDMI to the the 27', both 4K on my previous Mac Mini without any issues.I am going to upgrade the Intel based Mac Mini to Big Sur and see if I have the same issue. I have a 43' 4K Dell USB-C to Display Port, and 27' 4K USB-C to display port. > Has anyone had a similar issue? Is there anything else I could try to get the HDMI port working before restoring? I will be doing a downgrade and Time Machine restore to Catalina in the next couple days to see if the Big Sur update broke the HDMI port, or if it’s a hardware issue. Diagnostics Test (result: no issues found).HDMI monitor not showing up in Display settings.Unplugged all peripherals except for the HDMI monitor (result: no output).Confirmed the HDMI cable is fine (it works with another computer and the other monitor).Upon first boot into Big Sur after the update, one monitor wasn't working (the one with HDMI). Monitor 2: USB-C/Thunderbolt to DisplayPort I have a dual 4K monitor setup which has worked fine since I bought the computer. I just updated my Mac mini 2018 to Big Sur, and the HDMI port no longer works.

Hdmi not working mac mini