My edge light is set to always and it works fine when the screen is on and a notification comes through but it doesn't work when the screen is off and locked.
same here, it works only with Samsung apps but doesn't with Whatsapp and Gmail.... veeery annoying!
Edge lightning works with Whatsapp, provided you go to Settings -> Notification -> Popup notification -> No popup
So yours works at the lock screen with messages
Correct, but my setting is set to 'While screen is off'. You can enable popup notifications for the specific applications if you want that.
Yes it does, i tried sending sms messages from another phone and the lockscreen lights up, also with Edge Light.
Whatsapp and Gmail, the phone vibrates only and the screen remains dark.