Monitoring Logstash with Metricbeat

Hello,
I'm trying to monitor Logstash with Metricbeat.
I already enabled Elasticsearch X-Pack with metricbeat.
I followed instructions regarding Logstash monitoring with metricbeat.
In "Stack monitoring", i can see my Logstash node.
In Elasticsearch, i can see my index ".monitoring-logstash-7-mb-2021.07.02" getting bigger, and in the stack monitoring, when i use setup mode, i can see that my logstash node is "Monitored with Metricbeat" so i guess my configuration is correct.
My issue is, when i click on my logstash node in order to have detailed informations in Kibana, i have an error message saying :

Monitoring Request Error

[search_phase_execution_exception] : Check the Elasticsearch Monitoring cluster network connection or the load level of the nodes.

HTTP 503"

But i have no informations in elasticsearch, logstash, or metricbeat logs ...
The only message i have is in Kibana logs :

{"type":"log","@timestamp":"2021-07-02T11:23:20+02:00","tags":["error","plugins","monitoring","monitoring"],"pid":13250,"message":"StatusCodeError: [search_phase_execution_exception] \n at respond (/usr/share/kibana/node_modules/elasticsearch/src/lib/transport.js:349:15)\n at checkRespForFailure (/usr/share/kibana/node_modules/elasticsearch/src/lib/transport.js:306:7)\n at HttpConnector.<anonymous> (/usr/share/kibana/node_modules/elasticsearch/src/lib/connectors/http.js:173:7)\n at IncomingMessage.wrapper (/usr/share/kibana/node_modules/lodash/lodash.js:4991:19)\n at IncomingMessage.emit (events.js:327:22)\n at endReadableNT (internal/streams/readable.js:1327:12)\n at processTicksAndRejections (internal/process/task_queues.js:80:21) {\n status: 500,\n displayName: 'InternalServerError',\n path: '/.monitoring-logstash-6-*%2C.monitoring-logstash-7-*%2Cmetricbeat-*/_search',\n query: {\n size: 1,\n ignore_unavailable: true,\n filter_path: 'hits.hits._source.logstash_stats.events,hits.hits._source.logstash_stats.jvm.uptime_in_millis,hits.hits._source.logstash_stats.logstash,hits.hits._source.logstash_stats.queue.type,hits.hits._source.logstash_stats.reloads,hits.hits._source.logstash_stats.timestamp'\n },\n body: {\n error: {\n root_cause: [],\n type: 'search_phase_execution_exception',\n reason: '',\n phase: 'fetch',\n grouped: true,\n failed_shards: [],\n caused_by: [Object]\n },\n status: 500\n },\n statusCode: 500,\n response: {\"error\":{\"root_cause\": [ ],\"type\":\"search_phase_execution_exception\",\"reason\":\"\",\"phase\":\"fetch\",\"grouped\":true,\"failed_shards\":[],\"caused_by\":{\"type\":\"class_cast_exception\",\"reason\":\"class java.lang.Long cannot be cast to class org.apache.lucene.util.BytesRef (java.lang.Long is in module java.base of loader 'bootstrap'; org.apache.lucene.util.BytesRef is in unnamed module of loader 'app')\"}},\"status\":500},\n toString: [Function (anonymous)],\n toJSON: [Function (anonymous)]\n}"}

Do you have any idea why i can't have detailled informations ?

Many thanks

Regards

Hello,

Sorry to up this topic, but i'm completely lost with this issue.
Now i added Elasticsearch & Kibana monitoring with Metricbeat, everything works fine.
As i said concerning Logstash, i can view my infos with "Overview" and "Pipelines", but when i go in "nodes" tab and i click on my logstash node, i got the error i mentionned in my first post.
Hope it helps.
Thanks for help.

Regards

Well, i completely reinstalled Logstash with exact same options / configurations, now it's working...
#Magic