Final field in grand parent are not serialized

[logicinplay]

When a class extend an abstract class that also extends another abstract class, the final field are not serialized. Example:

A extends FooBar<String>
FooBar<T> extends Bar<T>
Bar<T> extends Foo
Foo { final MyEnum myEnum } // myEnum is not serialized

// or
B extends Bar<String>
Bar<T> extends Foo
Foo { final MyEnum myEnum } // myEnum is not serialized

Full example

abstract class Foo {
  final MyEnum myEnum;

  String? name;

  Foo({required this.myEnum});
}

abstract class Bar<T> extends Foo {
  T? value;

  Bar({required super.myEnum});
}

abstract class FooBar<T> extends Bar<T> {
  final MyOtherEnum myOtherEnum;

  final String? otherName;

  FooBar({required this.myOtherEnum, this.otherName})
      : super(myEnum: MyEnum.fooBar);
}

@JsonSerializable()
class A extends FooBar<String> {
  A({required super.myOtherEnum, super.otherName});

  factory A.fromJson(Map<String, dynamic> json) => _$AFromJson(json);

  Map<String, dynamic> toJson() => _$AToJson(this);
}

@JsonSerializable()
class B extends Bar<String> {
  B() : super(myEnum: MyEnum.b);

  factory B.fromJson(Map<String, dynamic> json) => _$BFromJson(json);

  Map<String, dynamic> toJson() => _$BToJson(this);
}

enum MyEnum { fooBar, b }

enum MyOtherEnum {
  one,
  two,
  three,
}

Generated toJson for A

Map<String, dynamic> _$AToJson(A instance) {
  final val = <String, dynamic>{};

  void writeNotNull(String key, dynamic value) {
    if (value != null) {
      val[key] = value;
    }
  }

  // all fields are here except `myEnum`
  writeNotNull('name', instance.name);
  writeNotNull('value', instance.value);
  val['myOtherEnum'] = _$MyOtherEnumEnumMap[instance.myOtherEnum]!;
  writeNotNull('otherName', instance.otherName);
  return val;
}

Generated toJson for B

Map<String, dynamic> _$BToJson(B instance) {
  final val = <String, dynamic>{};

  void writeNotNull(String key, dynamic value) {
    if (value != null) {
      val[key] = value;
    }
  }

  // all fields are here except `myEnum`
  writeNotNull('name', instance.name);
  writeNotNull('value', instance.value);
  return val;
}

Tried changing myEnum to private field with public getter with @JsonKey() but did not worked.
Removing final for myEnum works.

However, I myEnum should be a final field.

Is there any that I am missing? Any help would be greatly appreciated!