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, can you tell me the meaning? What can be couse of it?

Can you provide a bit more information please.
What is the full error? Is there anything in the Elasticsearch logs? What client is receiving this error?

Elastic log doesn't how anything. I am using elasticsearch-js client and that returns

Error: [illegal_argument_exception] encoded bytes are of incorrect length
Jan  6 01:55:35: at respond (/node_modules/elasticsearch/src/lib/transport.js:308:15)
Jan  6 01:55:35: at checkRespForFailure (/node_modules/elasticsearch/src/lib/transport.js:267:7)
Jan  6 01:55:35: at HttpConnector.<anonymous> (/node_modules/elasticsearch/src/lib/connectors/http.js:166:7)
Jan  6 01:55:35: at IncomingMessage.wrapper (/node_modules/lodash/lodash.js:4929:19)
Jan  6 01:55:35: at emitNone (events.js:111:20)
Jan  6 01:55:35: at IncomingMessage.emit (events.js:208:7)
Jan  6 01:55:35: at endReadableNT (_stream_readable.js:1055:12)
Jan  6 01:55:35: at _combinedTickCallback (internal/process/next_tick.js:138:11)
Jan  6 01:55:35: at process._tickCallback (internal/process/next_tick.js:180:9)