I have a cross-sectional view problem under "autodesk inventor", apparently several people have the same problem under other software.
It is a question of making a cross-sectional view that passes through the ribs. You don't have to cut the ribs but the software doesn't make a difference!
From memory, you have to do the same as for the screws. Right-click => hatching => remove the hatching (but I couldn't be more precise. I don't have the software at hand anymore)