Encoded bytes are incorrect length issue

Hi, my Elasticsearch 7.7.1 sometimes returns encoded bytes are incorrect length error with 400. It's only sometimes, when I do the same search again, it suddently works.
Can you tell me the meaning? What can be couse of it?

whole error looks like this

Nov 10 13:45:27 : Error: [illegal_argument_exception] encoded bytes are of incorrect length
Nov 10 13:45:27 : at respond (/elasticsearch/src/lib/transport.js:308:15)
Nov 10 13:45:27 : at checkRespForFailure (/elasticsearch/src/lib/transport.js:267:7)
Nov 10 13:45:27 : at HttpConnector.<anonymous> (/elasticsearch/src/lib/connectors/http.js:166:7)
Nov 10 13:45:27 : at IncomingMessage.wrapper (/node_modules/lodash/lodash.js:4949:19)
Nov 10 13:45:27 : at emitNone (events.js:111:20)
Nov 10 13:45:27 : at IncomingMessage.emit (events.js:208:7)
Nov 10 13:45:27 : at endReadableNT (_stream_readable.js:1055:12)
Nov 10 13:45:27 : at _combinedTickCallback (internal/process/next_tick.js:138:11)
Nov 10 13:45:27 : at process._tickCallback (internal/process/next_tick.js:180:9)

What is the full output of the cluster stats API?

{
   "_nodes":{
      "total":1,
      "successful":1,
      "failed":0
   },
   "cluster_name":"elasticsearch",
   "cluster_uuid":"zHHnwGX8RIC15uz3uIsEBw",
   "timestamp":1637571508023,
   "status":"yellow",
   "indices":{
      "count":47,
      "shards":{
         "total":94,
         "primaries":94,
         "replication":0.0,
         "index":{
            "shards":{
               "min":2,
               "max":2,
               "avg":2.0
            },
            "primaries":{
               "min":2,
               "max":2,
               "avg":2.0
            },
            "replication":{
               "min":0.0,
               "max":0.0,
               "avg":0.0
            }
         }
      },
      "docs":{
         "count":197259221,
         "deleted":0
      },
      "store":{
         "size_in_bytes":74936524928
      },
      "fielddata":{
         "memory_size_in_bytes":7055976,
         "evictions":0
      },
      "query_cache":{
         "memory_size_in_bytes":31184424,
         "total_count":352139,
         "hit_count":95579,
         "miss_count":256560,
         "cache_size":3898,
         "cache_count":5766,
         "evictions":1868
      },
      "completion":{
         "size_in_bytes":0
      },
      "segments":{
         "count":1769,
         "memory_in_bytes":37867364,
         "terms_memory_in_bytes":24114656,
         "stored_fields_memory_in_bytes":1527784,
         "term_vectors_memory_in_bytes":0,
         "norms_memory_in_bytes":2045696,
         "points_memory_in_bytes":0,
         "doc_values_memory_in_bytes":10179228,
         "index_writer_memory_in_bytes":23334364,
         "version_map_memory_in_bytes":0,
         "fixed_bit_set_memory_in_bytes":0,
         "max_unsafe_auto_id_timestamp":1637539201224,
         "file_sizes":{
            
         }
      },
      "mappings":{
         "field_types":[
            {
               "name":"boolean",
               "count":25,
               "index_count":24
            },
            {
               "name":"date",
               "count":140,
               "index_count":47
            },
            {
               "name":"float",
               "count":1445,
               "index_count":47
            },
            {
               "name":"geo_point",
               "count":47,
               "index_count":24
            },
            {
               "name":"integer",
               "count":24,
               "index_count":24
            },
            {
               "name":"ip",
               "count":50,
               "index_count":24
            },
            {
               "name":"keyword",
               "count":2485,
               "index_count":47
            },
            {
               "name":"long",
               "count":448,
               "index_count":47
            },
            {
               "name":"object",
               "count":166,
               "index_count":47
            },
            {
               "name":"short",
               "count":1,
               "index_count":1
            },
            {
               "name":"text",
               "count":999,
               "index_count":47
            }
         ]
      },
      "analysis":{
         "char_filter_types":[
            
         ],
         "tokenizer_types":[
            
         ],
         "filter_types":[
            {
               "name":"ngram",
               "count":24,
               "index_count":24
            }
         ],
         "analyzer_types":[
            {
               "name":"custom",
               "count":47,
               "index_count":24
            }
         ],
         "built_in_char_filters":[
            
         ],
         "built_in_tokenizers":[
            {
               "name":"whitespace",
               "count":47,
               "index_count":24
            }
         ],
         "built_in_filters":[
            {
               "name":"lowercase",
               "count":1,
               "index_count":1
            }
         ],
         "built_in_analyzers":[
            {
               "name":"whitespace",
               "count":95,
               "index_count":24
            }
         ]
      }
   },
   "nodes":{
      "count":{
         "total":1,
         "coordinating_only":0,
         "data":1,
         "ingest":1,
         "master":1,
         "ml":0,
         "remote_cluster_client":1,
         "transform":1,
         "voting_only":0
      },
      "versions":[
         "7.7.1"
      ],
      "os":{
         "available_processors":12,
         "allocated_processors":12,
         "names":[
            {
               "name":"Linux",
               "count":1
            }
         ],
         "pretty_names":[
            {
               "pretty_name":"CentOS Linux 7 (Core)",
               "count":1
            }
         ],
         "mem":{
            "total_in_bytes":67324633088,
            "free_in_bytes":634839040,
            "used_in_bytes":66689794048,
            "free_percent":1,
            "used_percent":99
         }
      },
      "process":{
         "cpu":{
            "percent":1
         },
         "open_file_descriptors":{
            "min":1822,
            "max":1822,
            "avg":1822
         }
      },
      "jvm":{
         "max_uptime_in_millis":1796587209,
         "versions":[
            {
               "version":"14.0.1",
               "vm_name":"OpenJDK64-Bit Server VM",
               "vm_version":"14.0.1+7",
               "vm_vendor":"AdoptOpenJDK",
               "bundled_jdk":true,
               "using_bundled_jdk":true,
               "count":1
            }
         ],
         "mem":{
            "heap_used_in_bytes":17959440896,
            "heap_max_in_bytes":27917287424
         },
         "threads":102
      },
      "fs":{
         "total_in_bytes":1062303657984,
         "free_in_bytes":857455890432,
         "available_in_bytes":813153263616
      },
      "plugins":[
         
      ],
      "network_types":{
         "transport_types":{
            "security4":1
         },
         "http_types":{
            "security4":1
         }
      },
      "discovery_types":{
         "zen":1
      },
      "packaging_types":[
         {
            "flavor":"default",
            "type":"rpm",
            "count":1
         }
      ],
      "ingest":{
         "number_of_pipelines":1,
         "processor_stats":{
            "gsub":{
               "count":0,
               "failed":0,
               "current":0,
               "time_in_millis":0
            },
            "script":{
               "count":0,
               "failed":0,
               "current":0,
               "time_in_millis":0
            }
         }
      }
   }
}

Any idea?