A number of users running macOS Big Sur 11.1 or 11.2 are experiencing external display connection issues, according to reports across social media and support forums.
The issues appear to have started in macOS Big Sur 11.1, according to reports from Apple Support Communities, Reddit, and the MacRumors forum. The recently released macOS 11.2 update doesn't seem to have fixed all of the problems, and some reports indicate that it actually worsened them.
Although the issues are related to the use of external displays, users are reporting two different bugs. For example, some users are running into issues with USB-C ports failing to recognize external monitors. This specific issue appears to affect both HDMI and DisplayPort display connections, either directly connected to a Mac or routed through a hub.
Other reports indicate resolution problems with external displays. This issue seemingly prevents external displays from functioning at a 4K 60Hz resolution. Instead, displays are locked at 30Hz and may even be recognized only as 1080p HD displays.
The issues appear to be ongoing, and there doesn't appear to be a patch in the first macOS 11.3 beta. No functioning and reliable fix or workaround has been discovered for either problem.
20 Comments
Originally with my M1 Mac Mini I couldn't lower the resolution down to 1080p without it causing issues and now it will not allow me to go any higher than 1080p. If it's software-related and I just have to settle for 1080p on my 4k TV until it gets resolved, no big deal. If it's a hardware problem, well, I guess that's what I get for being an early adopter.
And this doesn’t include the half opaque display right before shut down that is happening to some 2020 iMacs with info available as to why at different forums (including Apple communities as well). Frustrating to see this happen after having this issue start within a month of having the computer and upgrading to Big Sur (didn’t happen with Catalina) and with three months and no clarity of what is going on with it and paying over $2000 for an iMac to have this happen:
With 11.1, macOS had major problems determining the resolution and refresh rate of my USB-C connected external BenQ EX2780Q to my 16" MacBook Pro. Usually booted into a lower resolution and/or 60Hz refresh rate rather than 144Hz. Switching the monitor off was a big no-no, as it'd lose the resolution or refresh rate again when switched back on.
With 11.2, it boots up to the right resolution and refresh rate so far. I have found, however, that if the monitor is switched off and the Mac then goes into sleep mode, switching the monitor back on and waking up the Mac can cause it to drop the resolution down - but then switching the monitor off and on again fixes it. But this doesn't happen all the time. So there appears to be some improvement (at least for me), but not by much.
I don't have any problem described in the article with my Mac mini M1. However there is the very annoying problem that no good calibration software works on the M1. All developers (LG, Nec, X-Rite) point to a problem at Apple.