Unfolding doesn’t return the metal sheet in the same position

Dear all,

I have a problem while after folding the sheet metal doesn’t return into the same position as it was before I made unfolding. Below are the pictures for better understanding. Can somebody help me and explain why this happening and what I’m doing wrong? What do I have to change when doing unfolding so after the folding material will go exactly into the same position as it was before?

Thank you.

SolidworksSheet Metal