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First is to set Require password immediately so that you are always prompted to authenticate from the screensaver or from sleep. The second setting is found by clicking the padlock, then the Advanced button and it’s the tickbox tick box marked Turn on screen saver when login token is removed. This is shown below.BILD
It’s worth noting this option only appears after a smart card device has been paired to a macOS user. The combination of those two settings will cause your Mac to automatically lock and immediately require the password (and only from the Smart Card!) before letting you back in.
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