This probably is not the answer, but is the light slab actually slightly behind the section line, and is therefore not actually getting cut?
Or is there some other element (another slab or a beam or wall - could be in a hidden layer) that is automatically trimming the slab away?
Actually I think that will be it.
I just tested 2 slabs in the same place and in section you do not see the perimeter lines of the cut slabs.
Barry.
One of the forum moderators.
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