Springs.FamilyInstance.ByGeometry not including all surfaces of solid

Looks very similar to the below situation:

Try exporting the geometry to a sat file with the “Geometry.ExportToSAT” node and then manually importing it in revit. If it fails, then revit just can’t handle it. If that’s the case, you could try to perform additional surface simplification by using the “Surface.ApproximateWithTolerance” node on all curved surfaces of the solid.