JSON does not Encode/Decode subclass properties

Using the simplest possible class structure and defaulting everything, subclass String properties are not encoded nor decoded. Base class properties no problem. Here is the class structure, the test code which demonstrates the problem is given as an attachment. This is a much simpler case than SR-4772 and SR-5125.

class Product: Codable {
var family: String = ""
}
class SubProduct: Product {
var name: String = ""
}