Some users of macOS Big Sur who are running update 11.1 and recently released 11.2 have faced ongoing problems with external monitors, based on various reports in the MacRumors forum, Apple Support Communities, Twitter and Reddit.
/article-new/2020/11/macbook-pro-touch-bar-m1.jpg?resize=560%2C462&ssl=1)
There are at least two separate problems at play, but both are related to the external monitor connections. The problems appear to have started with the macOS Big Sur 11.1 update, and update 11.2 did not provide a fix and, in some cases, made the problem worse.
The first problem causes USB-C ports to not recognize external monitors, making external monitors unusable and unable to connect. This appears to be affecting DisplayPort and HDMI screens connected directly and through hubs and adapters.
Warning – the Big Sur 11.2 update is breaking USB-C ports for many. I lost my second monitor and now I can only use HDMI. Apple support was not fixed, so I think I’ll wait on 11.3 to fix the 11.2 update that should fix the external monitor problems. @Apple @Border @AppleSupport
– Jason Sedlaczek (@jasonsed) February 3, 2021
We saw this problem first hand after upgrading a MacBook Pro to macOS Big Sur 11.2, with the update preventing an external monitor from connecting with USB-C, and there are several other complaints from affected users. From Reddit:
Upgrading to 11.2 broke my second external monitor connection.
Primary monitor LG Ultrafine 4k (Mac version) connected via Thunderbolt.
The secondary monitor (same model) connected via HDMI-> DisplayPort adapter (BENFEI), and the DisplayPort-> USB-C cable no longer works after the update (it worked fine in 11.1 before the update).
MacOS seems to recognize the monitor and resolution, as shown in the video settings, and Apple support was able to remove it to my computer and see both screens. It is almost as if the signal for the monitor to turn on is not being sent.
The second problem results in resolution problems with external monitors unable to operate at a full resolution of 4K 60 Hz, instead blocked at 30 Hz. In some cases, a 4K monitor is only recognized as 1080p.
MacOS Big Sur 11.2 does not fix the problem I am having with the M1 MacBook Pro, in which my external monitor is locked at 30 Hz, despite being capable of 60 Hz 😞. – Patrick O’Rourke (@Patrick_ORourke) February 2, 2021
It appears that many of those affected with display problems have a 16-inch MacBook Pro, but there are also reports of other Macs with the same connectivity issues. There does not seem to be a reliable fix or workaround that is currently widespread and tested.
Mac users did not experience these problems in the initial release of macOS Big Sur 11.0.1 and it appears that the macOS Big Sur 11.3 update released yesterday does not solve the problem either, but there is still some time for Apple to work on a fix before it 11.3 software is released to the public.