If you are talking about the little "hump" in the middle of the top/horizontal leg, my 9mm Shield's spring has the same " little hump".
Once you get the spring back into its recess, just gently go along the entire spring and press inward to push it fully into its recess.
After reading about this issue on this Forum, with the early Shield's, I checked both my 9mm and my 45acp, neither were completely seated. In the gunshop where I worked at the time, I just made it standard practice to check all of the Shields that came in the shop. Found a few that needed a slight nudge.