Error generating toJson for Generic freezed class with freezed class as T

[socramm9]

I have this Freezed Class that I want to use for DataModel loaded from my Backend

@Freezed(genericArgumentFactories: true)
class DataModel<T> with _$DataModel {
  factory DataModel({
    required String id,
    required bool loading,
    required DateTime lastLoaded,
    required T? data,
  }) = _DataModel;

  factory DataModel.fromJson(
    Map<String, dynamic> json,
    T Function(Object?) fromJsonT,
  ) =>
      _$DataModelFromJson(json, fromJsonT);
}

This generates fine. Next Step Would be to use this class with my Data class and State class. Here a example Using my UserModel.

@freezed
class User with _$User {
  factory CrUser({
    required String id,
    required String fullName,
    required String email,
  }) = _User;

  factory User.fromJson(Map<String, dynamic> json) => _$UserFromJson(json);
}

This also generates fine. But if i try to use it together with DataModel:

@freezed
class UsersCubitState with _$UsersCubitState {
  const factory UsersCubitState({
    required Map<String, DataModel<User>> users,
  }) = _UsersCubitState;

  const UsersCubitState._();

  factory UsersCubitState.initial() =>
      const UsersCubitState(users: {});

  factory UsersCubitState.fromJson(Map<String, dynamic> json) =>
      _$UsersCubitStateFromJson(json);
}

I get following error:

[SEVERE] json_serializable on lib/features/users/cubit/users_cubit.dart:

RangeError (index): Invalid value: Only valid value is 0: -1

I don't really know what do do with this error message...

Im I doing something wrong? If necessary I can provide a minimal repository to reproduce this error if needed.

Expected behavior
I would expect to generate my Class without an error.

[socramm9]

Closing my Issue Found solution here #766