Sadly this is a longstanding shortcoming for the floorplan views with walls. The projected display of walls is not a true 3D projection.
The only way we've managed to fix this is by using window openings to make the cut and setting those to projected instead of symbolic.
The entire wall will also affect your zones if the wall is set as zone boundary.
Especially for dormer windows, this make things a bit fiddly.
Erwin Edel, Project Lead, Leloup Architecten
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