I have been using my Note 20 Ultra 5G since around a week now. I have set up the Secure Folder and have set up password + fingerprints authentication for this. I have also put the Secure Folder icon on the phone's Home screen, for quick access. Hence, every time I want to enter the Secure Folder, I should have to provide either the password or a fingerprint.
However, today I noticed that if I try to enter the Secure Folder by tapping on the icon I have placed on the Home screen, it does not authenticate my identity at all. No prompt for password/fingerprint at all. Just takes me straight to the Secure Folder
On the other hand, if I click on a notification on the top bar that pertains to a Secure Folder app, then it does ask for authentication.
On digging a bit further, I realised the Secure Folder options have been changed on this phone compared to earlier Note phones. Now you have to go into Settings > Biometrics and security > Secure Folder, and then in the 'Auto lock Secure Folder' settings, you have to choose "Immediately". Only then it locks the Secure Folder every time you get out of it. Otherwise someone might have easy access to it while you are away from your phone for a few minutes.
Thought I would post this in case it helps someone. Samsung should have kept this "Immediate" locking as the default, but they haven't. It could catch many people unawares.