image "bevel" problem

I'm having a problem with images inserted in Storyline 2. My slide master has a white box on it, sized 546 x 890 and positioned at 35 h, 135 v. When I place an image on top of the white box, at the same size and same coordinates, I get what looks almost like a bevel at the top and left (see attached).

I found out in another discussion that Storyline seems to by default add a shadow to photographs. Can someone help me figure out why my image looks like this and how to fix it?

Thank you!