An unknown number of Apple Silicon users who have linked two or more accounts on their M1 Mac are currently facing an annoying user switching bug.
Apple's Fast User Switching, introduced in 2003 with OS X Panther, is reportedly causing issues with some M1 Macs. The feature allows users to create more than one login account on their Mac, including a guest account, and switch between them. However, this switching feature is reportedly activated unexpectedly. reported the US blog MacRumors:
A growing number of user reports online suggest that some of Apple's M1 Mac models are vulnerable to a fast user switching bug that spontaneously activates the screen saver and leaves the user unable to exit it.
In macOS Big Sur, Fast User Switching allows you to quickly switch between user accounts without having to log out completely. However, based on posts on the MacRumors forums, Apple Community, and Reddit, a screen saver can sometimes take over the screen of Apple Silicon Macs without notice, making the desktop workspace completely inaccessible.
Fast User Switching: Just an M1 Mac Problem?
While the screen saver is activating, the mouse pointer is still visible at the top and moving. To end the unwanted state, users have to close their MacBook Air / Pro and open it again. Alternatively, the whole thing can be ended by pressing the Power / Touch ID button or using the key combination Alt-Command-Q. The system then returns to the login view. It is questionable whether the bug actually only occurs on M1 Mac devices. So far, at least one report has been documented that the whole thing also occurred on an Intel Mac under macOS Big Sur. (Image: Apple)