Sounds like it's time to go back to shooting paper for a bit to see what's wrong. Could be your gun is shooting to a different sight picture that you're using. (among other possibilities)
I've been enjoying a partial implementation of the Dot Torture Drill.
I put up a Post-It note or 3 then step back 3 paces. Getting all the shots on a post-it, even at that close range is surprisingly difficult - even slow fire.
If it's too easy, just step back 2 more paces.