Offset Curve not working

Heyy, Im pretty new to grasshopper, and I created a facade with vertical planes as shown on the pictures, but now I wanted it to be horizontal, instead of vertical, I was following the same logic as I did before only now dividing the surface horizontally, but when I tried offsetting the curve, it gives me these weird curves, so I tried changing the plane to the normal vector of the surface instead, but it still gives me this strange result, could somebody help me please? I disabled the components that are too heavy btw, the problem is highlighted on my canvas on the top right corner. Thanks!! (140.5 KB) (135.3 KB)