When Section plane is set to effect Current Layer, it has no effect on the Scatter, just the surface the Scatter is applied on. Only when it’s set to effect All Layers it works.
The believe same is true when applying Brush of Grass material to a surface.
This is a known behavior due to how Scatter and brush-generated grass are handled in D5 — procedural objects are not included when clipping a single layer.
To help us investigate further, could you share:
A short screen recording showing the Section Plane behavior in both Current Layer and All Layers modes.