Google Pixel 4 and Pixel 4 XL are completely relying on face unlock authentication as they don’t have fingerprint sensor anywhere. This because of the advance technology used by google and it should be as secure as Apples Face ID but unfortunately there’s a thing where both technologies differ.
Users have found out that Google Pixel’s Face unlock works even if the eyes are closed. This would be an issue because if someone want to unlock your phone, they just need to put it in front of your face. This can create problems when the people in your home can access your phone even if you are sleeping. It is unclear that whether it is a bug or the implementation of this feature made in this way.
This has created confusion among the users and hopefully google will send out a software update to fix this issue.