Questionnaire loading error

[V-B]

I'm trying to get questionnaire items in my application by graphQL and after updated (I think) Survey Solutions from 22.06.4 to 22.06.9 it is not working.

public async Task<GraphQlResponse> Get_questionaireItems()
        {
            var builder = new HeadquartersQueryQueryBuilder()
                .WithQuestionnaireItems(
                new QuestionnaireItemQueryBuilder()
                .WithAllFields(),
                cbox_ws.SelectedItem.ToString(),
                questFilter.QuestionnaireId,
                questFilter.Version
                );
            var result = await clientWS.GraphQl.ExecuteAsync<GraphQlResponse>(builder);
            return result;
        }

I got error message by SurveySolutionsClient.GraphQl.QueryError

There was a problem converting an DbDataReader to NDataReader