SNAP is quite sensitive to invalid geometries. Run the fix geometries tool in QGIS, there might be topological errors which are not visible.
The fact that only some polygons were imported underlines this indication, I had a similar case once.
SNAP is quite sensitive to invalid geometries. Run the fix geometries tool in QGIS, there might be topological errors which are not visible.
The fact that only some polygons were imported underlines this indication, I had a similar case once.