big sur – Unlock MacOs with fingertips doesn’t work on Big Sur

I’m trying to unlock my MacOS Big Sur with a fingertip. During the initialisation process, I configured my fingertip correctly but when I try to unlock my MacOS it doesn’t detect it.

If I go in “System Preferences” under the menu “Touch ID” this is what I see:

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Then I decided to check the “Unlocking your Mac” option, I fill the password but if I open “Touch ID” for the second time “Unlocking your Mac” is still unchecked.

Why? What can I do?