3ds max question . Uv map copy

Hi guys .
i know we must ask the only unreal question not 3ds max question but if any one can help I will be appreciated.
i trying creat light map for unreal with headus . first i export (.obj ) my object to headus after I creat my light map in headus i go back to max and import my object in to max but when I want copy Uv from a object to the same object i get broken uvs or its doesn’t work. any one have a solution for this problem?
pleas remember objects have the same polygon and vertex number.

pleas help im going crazy.

thanks .