IFC2x3 Does Not Include Walls If the Slab Penetration Extends Beneath Them.

Problem Description: 

If a slab penetration extends slightly underneath a wall, that wall will not export to IFC.

Steps to Resolve: 

Export to IFC4 instead of IFC2X3 to include the wall.

The wall is included after exporting to IFC4.                                  The wall is not included exporting to IFC2x3