I'm having what seems to be a similar issue that started on Monday. I have an S4 for work and usually have the pattern option set for my lock screen and it would normally look like this:
and punching in the pattern would bring me straight to my home screen:
However, on Monday morning the phone lock screen page looked a little different:
But after putting in the proper pattern it takes me to what I figure is the swipe to unlock screen:
I've changed my lock screen settings selection from "Pattern" to "Swipe" to "None" but the lock icon page won't go away when I'm unlocking the phone. I've restarted the phone and tried pretty much anything I can think of with no success. It's pretty annoying.