Why does picking up an object override my rotation freeze setting?

Trying to work in a 2D environment - where the z is fixed.

My Player object has a character controller, and also a rigid body with z position & z rotation frozen.

I attempt to pick up a block with the following code:

 private void PickUp(GameObject target)
 {
     carriedObject = target.transform;
         
     if( carriedObject != null )
     {
         Destroy( carriedObject.rigidbody );
         carriedObject.parent = transform;
         carriedObject.localPosition = new Vector3( 2f, .5f, 0); 
     }
 }

It looks like doing this affects the player game object, and removes the "Freeze Rotation Z" from my player entity? When I bump into another object, I start spinning on the Z axis. It seems like no matter how I set the localPosition of my carried object (inside the bounds of the player, outside the bounds, somewhere out in space on the z axis...) I get the same effect.

Is there a tutorial out there I should be following? Does anybody have any pointers to help me "carry" an object? Should I instead be "wearing" the object?

Any advice is appreciated!