datasmith revit converting coordinate systems

Hello guys,
i built the Revit DataSmith exporter plugin from the git source file, but now when i export .udatasmith in Revit and import them in Unreal, the whole room is flipped in the Y axis, and all the normals are also flipped, so I have to go into modeling mode in Unreal and select each geometry and repair the normals.
with the original Revit Datasmith plugin (the one that we install using .msi file), this does not happen and the 3d models go beautifully into Unreal without any flipping or dislocation.

have you ever had this experience?
do you know what i have to do?
I searched inside many CS files in the private folder and edited some parts, but this did not fix.

Thank you for your help and attention.