how to move a part of the circuit with out changing the routing and placement of it

Hi all,

I have a circuit containing 2 parts. I used logiclock to constrain them into specific regions. Now I want to move the second part around.

I hope to keep the routing and placement of both of them, especially the second part, the same. It means the placement of the second part should only be changed by linearly transforming the whole part into a different place.

But every time I do it, even I keep the net-list as post-fit when recompile, the layout of the moving part still looks different. Do you guys have any idea?

Thank you

:)