Weldments Issue

Hi,

I am having a problem with my weldments cut list.

When I mirror some parts it applies them to 2 different items (even though they are the exact same component). The example is shown below:-

as you can see, I have this component and it comes up as 1 part in the cut list. But now when I do just a mirror, it changes them into 2 even though it is exactly the same geometry and component. (shown Below)

Any suggestions as this isn't the only part that its doing it with?

I want to have them in the same cut part, so it shows up on the weldment table as a quantity of 2 and I can show the boundary box sizes (without adding any more features or making the design tree larger (as it is already quite big and slow for a Solidworks part).

Thanks

SolidworksWeldments