The parent transform affects the children, here, the RigidBody2D is child of the Sprite, parent movement may affect the body but the physics engine will do that too producing an undesired situation.
When you make a CollisionObject based scene, you need to create it this way
Body on root (+script if needed)
|-Sprite (or whatever is the visual representation)
|-Shape1 (if added with the editor)
|-All extra things that depends on body movement