Why aren't they convergent?

[dancheng9999]

package student

type Person struct {
name string
}

type Student struct {
person Person
}

run command
goplantuml -recursive -output ./uml/main.puml ./

@startuml
namespace student {
class Person << (S,Aquamarine) >> {
- name string

}
class Student << (S,Aquamarine) >> {
    - person Person

}

}

@enduml