Closed corners/half-lap tapering the edges?

Hi all,

I'm running into an interesting issue here using closed corners. I have a 60° flange, with a 90° flange adjacent to it. I'm using a closed corner to give a half-lap where these two edges meet, for welding later on.

One would think SW would offset the faces of the edges to achieve the desired over/under lap ratio, however it is extending/cutting the edges with a taper. I'm not sure yet how it is calculating this angle, but it is strange to me. Any ideas if it's simply me missing a checkbox somewhere?

See attached image for clarity.

SolidworksSheet Metal