Each line was selected as 5 induvial line segments instead of a single open contour.
Sideway compensation was set to left instead of center.
Left Sideway compensation is used for closed standard contours (closed shapes)
Center Sideway compensation is used for open contours (lines)
Also when cutting line you want NO lead ins outs or pierce clearances.
I changed a few things around in your file to reflect the workflow I prefer.
Shelf tin mod v1.f3d (396.6 KB)
check out this video that walks through the workflow of single line cutting in fusion
check out the workflow and get back to us with any other questions
