Storyline will not allow me to create smaller shapes to the exact size that I need.

I am trying to cover sensitive information in my project. When I am trying to cover something small like the name of a user in the "user name" box. I can get the shape to just a certain size and then when I try to make it smaller it snaps the the next set of sizing handles (showing pink lines as it does). I need to find a way to (hopefully) turn this feature off. Can someone please explain how I can make the shapes the size I need them to be?

Thanks,

Mame