我正在尝试实现一个示例代码，它使用ElasticSearch的建议特性。
索引文档由一个平面poco组成

public class CandidateDocument
{
    public Guid Id { get; set; }
    public string Name { get; set; }
    public string FirstName { get; set; }
    public DateTime BirthDate { get; set; }
    public CompletionField Suggest { get; set; }
}

Map如下

var client = new ElasticClient(settings);

client.Indices.Create("candidates", c =>
                                           c.Map<CandidateDocument>(m =>
                                                            m.Properties(ps => ps.Text(s => s.Name(n => n.Name)
                                                                                             .Store(false)
                                                                                             .Fields(f => f.Keyword(k => k.Name("nameRaw"))))
                                                                                 .Text(s => s.Name(n => n.FirstName)
                                                                                             .Store(false)
                                                                                             .Fields(f => f.Keyword(k => k.Name("firstNameRaw"))

                                                                                 .Date(s => s.Name(n => n.BirthDate).Format("ddMMyyyy"))
                                                                                 .Keyword(s => s.Name(n => n.Id))))

                                                                                 .Completion(c => c.Name(n => n.Suggest)))));

为文档编制索引的方式如下：

var candidateDocument = new CandidateDocument
        {
            Id = Guid.NewGuid(),
            Name = "Lennon",
            FirstName = "John",
            BirthDate = DateTime.Now,
            Suggest = new CompletionField
            {
                Input = new[] { "Lennon" },
            }
        };

    var indexResponse = await this.elasticClient.IndexAsync(candidateDocument, i => i.Index("candidates"));

我的问题是：

var searchResponse = await this.elasticClient.SearchAsync<CandidateDocument>(s => s.Index("candidates").Suggest(su => su
                                                                                                       .Completion("suggestions", c => c
                                                                                                                                        .Field(f => f.Suggest)
                                                                                                                                        .Prefix(query)
                                                                                                                                        .Fuzzy(f => f.Fuzziness(Fuzziness.Auto))
                                                                                                                                        .Size(5))));

我面临着一个问题如下：
elasticsearch.net.elasticsearchclientexception:请求未能执行。呼叫：状态码400发件人：post/candidates/\u search？键入的\u keys=true。servererror:type:search\u phase\u execution\u exception reason:“all shards failed”causedby:“type:illegal\u argument\u exception reason:“找不到字段[suggest]的Map”causedby:“type:illegal\u argument\u exception reason:“找不到字段[suggest]的Map”
使用kibana查看我的索引Map：

"suggest": {
      "properties": {
        "input": {
          "type": "text",
          "fields": {
            "keyword": {
              "type": "keyword",
              "ignore_above": 256
            }
          }
        }
      }
    }

顺便说一下，我在.NETCore3.1中使用的是最新版本的nest（7.9.0）
我会感激你的帮助。