A bug with macOS Big Sur screensaver and fast user switching is causing M1 Macs to become unresponsive. When the screensaver activates, using the keyboard or mouse/trackpad does not dismiss it, and the issue is only fixed by putting the Mac to sleep and waking it up again.
Fast user switching is a feature in macOS that allows users to quickly move between different accounts on their Mac, without logging out of them.
M1 Mac users report macOS Big Sur screensaver issues
I have a brand new M1 MacBook Pro running macOS 11.1 and I’m having a small yet annoying issue. At random times, while in the middle of working, my machine will suddenly activate the screensaver. I cannot click out of it, and my keyboard does nothing. The only fix I’ve found is to close the MacBook for 4-5 seconds, then open it and upon reloading in, it fixes itself.
Users over at Apple Community forums and MacRumors forums have also reported this problem, with some reporting that the screensaver turns on randomly, even if it is disabled. A few users have reported that the latest macOS Big Sur 11.2 beta exhibits the same problem.
Apple had not responded to this issue yet, but it is expected that they will fix it in a future software update. If you are facing a similar issue, you can following the below workarounds for now:
- Disable fast user switching by going to System Preferences > Users & Groups > Login Options and unchecking the option which says ‘Show fast user switching menu as’. Note that this will disable fast user switching from the menu bar, but you can always go to the lock screen and switch accounts by pressing CTRL + CMD + Q buttons. This is a bit slower than fast user switching from menu bar, but it provides the same results.
- Use this command in Terminal to disable screensaver, as shared by Apple Support with a MacRumors forums user.
sudo defaults write /Library/Preferences/com.apple.screensaver loginWindowIdleTime 0
Are you facing this macOS Big Sur screensaver bug on your M1 Mac? Did the above workarounds help? Let us know in the comments below.