Hi. In some folders I have custom fields that are hidden. To see them, it asks me again for the master authentication key; it seems to me an error, since if someone logs into my account with the master password, they can also see those hidden fields since the password you ask for, is the same one you used to enter. I think that in those cases a second password or a numeric code should be used for that second layer of security.
@maraujo Welcome to the forum!
You can disable this behavior by editing the item and unchecking the check box for the option "Master password re-prompt ".
The purpose of this feature is to provide a barrier to make viewing of such items more challenging for any individuals who may have temporary access to your unlocked vault (e.g., you leave a device unattended or allow somebody to use your device while your Bitwarden app or browser extension is unlocked).
The master password re-prompt feature is not intended to guard against a scenario in which your master password has been disclosed, cracked, or otherwise compormised.