Curtain walls partly demolished

We have a project with a Curtain Wall and the bottom mullion is getting demolished. In revit we get the result we want, but as soon as we export it to IFC the mullion is visible in IFC.

For fillings like Windows (shared) the same problem occurs.

Is this a known issue?

Start by reproducing the curtain-wall export described in the issue, comparing the Revit result with the exported IFC and checking the same behavior for shared Window fillings. Done means determining whether demolished mullions and fillings are incorrectly included in the IFC and identifying the relevant export path to investigate.

Written by the indexing model from the issue text.