A possible bug in intersection of cone and cylinder

I meet a problem when making the intersection of cylinder with a cone, following is the code:

// make cone

TopoDS_Shape box1 = BRepPrimAPI_MakeCone(100, 0, 400);

// make a cylinder with a offset from X axis

gp_Ax2 ax2( gp_Pnt(-10, 0, -20), gp_Dir(0, 0, 1) );

TopoDS_Shape box2 = BRepPrimAPI_MakeCylinder(ax2, 10, 2000);


// make the intersection

TopoDS_Shape result;

BRepAlgoAPI_Common mkCommon( box1 /*main*/, box2 /*tool*/ );

result = mkCommon.Shape();

// calculate the volume of the intersection

GProp_GProps massProps;

BRepGProp::VolumeProperties( result, massProps );

double vol = massProps.Mass();

----------------------------------------------------

here, I get the volume of the intersection is 0; there is wrong.

However, when I make the offset of the cylinder as gp_Pnt(0, 0, 0), or gp_Pnt(10, 0, -20); which means the the offset for X >=0;  the volume of the intersection will become a reasonable value.

I also test the intersection of this cylinder with torus, box, etc., they are good, only cylinder meets this problem.

Whether I make any mistake in using the code, or there is a bug in the OCCT?  

BTW, I am using the OCCT v7.4.0.

Many thanks!