What the difference between meshes gneerated in Unity and in Blender, for example?

Hi all,

As the title says, I'm curious what the differences between meshes generated in various 3D programs? I have a procedural generated code that works for a Unity cylinder (and on original model in a FBX format) and I see a generated pipe and when I try to make a similar model in Blender and use it for this task, I see nothing - the pipe isn't created procedurally. I have tried many various cylinders made in Blender and none didn't work in Unity in my code. The code works with other Unity primitives too, but not with those made in Blender. I tried to import the original cylinder in FBX to Blender to see how it looks in this software, but the file is too old and therefore it cannot be imported.