That setting also changed on my lg g3 after updating to 6.0. The only difference is that now after tapping the screen twice, or lightly pressing the power button, the dial pad doesn't automatically display like it used to, which is cool with me. I love to see my wallpaper first.

i dont like it cuz i keep my phone in my pocket and i dont want it to unlock and dial someone without me knowing...

change to the pic you want on the lock screen.

its not the pic on my screen its how my phone unlocks

it's a different format.

when the phone is shutdown or idle for 24 hours the pin(or backup) is required to unlock if you setup fingerprint.

i dont have finger print setup just a pin number.

Keep in mind that if you are connected to a bluetooth device that you have set as trusted it won't lock fully and all you wil have to do is swipe the screen.