External displays experiencing issues on macOS Big Sur 11.1 and 11.2

Mac Mini M1 Chip
Mac Mini M1 Chip (Image credit: Apple)

What you need to know

  • macOS Big Sur 11.1 and 11.2 are causing issues for external displays.
  • Displays either won't work or can't show their full resolution.

As reported by MacRumors, some macOS Big Sur users who have upgraded to 11.1 and 11.2 are having continuous issues when hooking up their Macs to an external display. The issue appears to have been introduced in macOS Big Sur 11.1 and, unfortunately, the 11.2 update has either not fixed or, in certain cases, worsened it.

The first issue causes external displays not to be recognized by the USB-C port on the Mac, rendering the display useless.

The first issue causes USB-C ports to fail to recognize external monitors, rendering external displays unusable and unable to connect. This appears to be affecting both DisplayPort and HDMI displays connected directly and through hubs and adapters.

MacRumors says they experienced the issue themselves after upgrading a MacBook Pro to macOS Big Sur 11.2. Another user posted about the issue on Reddit:

Upgrading to 11.2 broke my second external monitor connection. Primary monitor LG Ultrafine 4k (Mac version) connected via Thunderbolt. Secondary monitor (same model) connected via HDMI->DisplayPort adapter (BENFEI), then DisplayPort->USB-C cable no longer works after updating (worked fine on 11.1 before updating). macOS appears to recognize the monitor and resolution, as it is shown in display settings, and Apple Support was able to remove into my computer and see both screens. It's almost as if the signal for the monitor to turn on is not being sent.

Benq Designvue 4K

Benq Designvue 4K (Image credit: iMore)

The second issue affects the ability of the external display to show content in full 4K 60Hz resolution.

The second issue results in resolution issues with external displays unable to work at a full 4K 60Hz resolution, instead locked at 30Hz. In some cases, a 4K monitor is only recognized as a 1080p monitor.

The macOS Big Sur 11.3 developer beta released yesterday and has not appeared to fix the issue either. However, there is plenty of time between now and the 11.3 public release, so hopefully, Apple will address it by then.

Joe Wituschek
Contributor

Joe Wituschek is a Contributor at iMore. With over ten years in the technology industry, one of them being at Apple, Joe now covers the company for the website. In addition to covering breaking news, Joe also writes editorials and reviews for a range of products. He fell in love with Apple products when he got an iPod nano for Christmas almost twenty years ago. Despite being considered a "heavy" user, he has always preferred the consumer-focused products like the MacBook Air, iPad mini, and iPhone 13 mini. He will fight to the death to keep a mini iPhone in the lineup. In his free time, Joe enjoys video games, movies, photography, running, and basically everything outdoors.

2 Comments
  • Big Sur had external display issues as far back as the beta. It bricked the HDMI port on my Intel Mac Mini. The workaround was to use a USB-C to HDMI adapter. My M1 Mini has been fine so far, but it sounds like they’re still having problems. Seems like it shouldn’t be such a big challenge to get something fundamental like this to work properly.
  • facing issue after mac mini m1 upgrade to 11.2.. external monitor does not display...the mac mini m1 is now in a bricked state