How doni hide contents of text messages with AOD on?

[Antmf]

I have AOD on and even though I have content hidden on locked screen send a notification pops up saying contents hidden there is another bigger pop up that display the whole message. Is that the way it works? Or can I fix that?

 

[anon(238680)]

AOD is essentially a blank screen with a clock and maybe a calendar depending on whether you have that turned on. It appears you're describing the lock screen which has nothing to do with AOD.
There are a couple places that contain settings for notifications, it sounds like you haven't set them all to off.