Flutter Code do not enter method called with Bloc > 7.2

Question

I tried copying the Code provided by ResoCoder (which is about 2years old from now). GitHub Project Therefore I had to migrate everything to the current BLOC Version 8.0.3. However I got stuck in the following:

SignInFormBloc(this._authFacade) : super(SignInFormState.initial()) {
on<RegisterWithEmailAndPasswordPressed>((event, emit) {
  print("Register");
  _performActionOnAuthFacadeWithEmailAndPassword(
    _authFacade.registerWithEmailAndPassword,
  );
});
}

//Here is the called method
Stream<SignInFormState> _performActionOnAuthFacadeWithEmailAndPassword(
Future<Either<AuthFailure, Unit>> Function({
  required EmailAddress emailAddress,
  required Password password,
})
    forwardedCall,
) async* {
print("first line");
Either<AuthFailure, Unit> failureOrSuccess =
    const Right<AuthFailure, Unit>(unit);

final isEmailValid = state.emailAddress.isValid();
final isPasswordValid = state.password.isValid();

if (isEmailValid && isPasswordValid) {
  print("if valid");
  yield state.copyWith(
    isSubmitting: true,
    authFailureOrSuccessOption: none(),
  );

  failureOrSuccess = await forwardedCall(
    emailAddress: state.emailAddress,
    password: state.password,
  );
}

yield state.copyWith(
  isSubmitting: false,
  showErrorMessages: true,
  authFailureOrSuccessOption: optionOf(failureOrSuccess),
);

}

The Code enter the call of on event, however the first Print-statement of the calles method is not triggered. Do someone have a hint why this could happen?