I'm on Ubuntu 16.04. Two home accounts were set.
One of them doesn't prompt for a password request at login page even though I have set a password for it. Is that a bug?
You can define an account where a password isn't required to login. Go to System Settings, User Accounts and call up the user profile. This screen appears:
If Automatic Login is set ON then no password is required to log on.
As https://askubuntu.com/users/367990/byte-commander pointed out in comments you can click on a user's password and this screen will appear:
Click on the Action drop down menu and select Log in without a password
Solved, ahah! For some reason I might have put my account into nopasswordlist. Further info:
How to get Ubuntu to ask for my password at login screen again?