That's just one power save mode - Battery Save. I thought maybe you were also referring to Expedition mode, which is a different sort of power saving mode. Both of these modes are intended to conserve battery (in different ways).
Screen lock is a different thing. It is intended to protect you against accidental taps - for example, while the unit is in your pack. Auto screen lock controls just when the screen automatically locks. I don't remember the details, but I believe the choices (when you enable auto-lock) have do with how long the unit waits after your last interaction and before automatically locking the screen. Once the screen is locked, you do need to briefly depress the power button to unlock.
I do not recall how power save interacts with screen lock - and it may have changed with this release. The reason I think the change might be intentional is that power save mode turns the screen off. You don't want to accidentally leave power save mode because the unit got jostled in your pack (accidental tap).
jvalesI am sending you a private message regarding the device shutting off. However, regarding the lock screen you will see when you turn battery save on you get a message explaining exactly what you are having happen. This is for battery save purposes so the screen doesn't accidentally come back on and drain battery.
Hy Leslie. I kind of figure it out that the lock screen was probably glinch in V9.20, which was useful for me :) . I saw this masage and I suspected that. Now it works like it says in the masage:)
This is 100% correct behavior!