Hidden Geometry appears in Generated Section

Hi all,

I imported a model via IFC, redid some surface to 3D solid, did some DMAudit, and when I create a Section (boundary), it appears like two slabs in the middle of the section.

I turned on all layers to check for hidden geometry. Also, I bimify the model, so it doesn't appear any lost 3D Solid in the Structure Browser.

Does anyone have an idea of what can be happening and how to look for a hidden geometry or if it is even a problem of section generation?

Thanks for any contribution,
Maurilio Lobato