A few days ago, we confirmed that the Pixel 4’s face unlock unlocks your phone even with your eyes closed. This poses a security risk as someone can unlock your phone while you are sleeping or dozing off. (Power off should should the problem).
Google responded to our query that they are working on an update that will be pushed out to the Pixel 4/4XL phones later.
We’ve been working on an option for users to require their eyes to be open to unlock the phone, which will be delivered in a software update in the coming months. In the meantime, if any Pixel 4 users are concerned that someone may take their phone and try to unlock it while their eyes are closed, they can activate a security feature that requires a pin, pattern or password for the next unlock. Pixel 4 face unlock meets the security requirements as a strong biometric, and can be used for payments and app authentication, including banking apps. It is resilient against invalid unlock attempts via other means, like with masks.