I've set screen saver settings to turn on after 60 minutes and "on resume, display logon screen". When I returned in the morning, I was brought to the desktop without a logon screen. However, I just changed it to turn on after 1 minute for testing, and I do get a password prompt after screen saver was activated. What can I do to get the logon screen every time?
You can 'Lock' your screen when you leave (ctrl+alt+del) to be sure that whoever uses the PC next has to log in.
There are a few things which can stop a screensaver from locking a session, possible windows/program updates may interrupt it... Or even a program waiting for a response/notification.