Google Pixel 4 introduced an advanced facial recognition system that serves as the phone's main authentication medium. However, it appears that some Pixel 4 and Pixel 4 XL users are now facing issues with the face unlock function following the last few Android security patches. Multiple reports of vexed Pixel 4 users have surfaced online on the official Pixel support forum as well as Reddit, detailing the face unlock problem, but so far, a concrete solution is yet to be discovered. For some users, the phone simply fails to recognise their face, while others are receiving notifications that they need to register their face data once again.
The issue has manifested in various forms for Pixel 4 users, who have reported about it on multiple platforms. In some cases, the face unlock system simply stopped working after installing the January security update. And when users try to wipe the existing face data, they reportedly see a “Cannot verify face” error message. For some users, they abruptly started receiving system notifications asking them to re-register their face again, despite the face unlock functioning fine.
But when users tried to re-register their face after wiping out the existing data, they get a “Can't verify face. Try again” message. The face unlock failure has been reported both while trying to unlock the phone or in apps. However, the problem is not universal and only a small number of people are apparently facing the face recognition issue on their Pixel 4. Interestingly, doing a factory reset makes the face unlock system work again on their Pixel 4. However, the solution apparently doesn't work for all users.
The error messages users are getting on their Pixel 4 also vary depending on the stage they are in. Some of the affected users have shared system screenshots of notifications that say “Face enrolment didn't work”. A reboot restores the face unlock function to normal again, but this solution doesn't work for all users either. Google is yet to acknowledge the issue officially and release a fix for it. However, the company is reportedly looking into the complaints of Pixel 4 users and might resolve it soon.