Warn dropped_data_points message. receivers prometheus and exporter Elastic APM

[mordp1]

Hello all!
I would like to configure the opentelemetry-collector to send Prometheus metrics to my APM Elastic, but I can experience some warning messages and would like your help on what the messages mean or how I can "extract" more details about this.

2024-05-17T09:17:58.765Z warn [email protected]/otlp.go:110 Partial success response {"kind": "exporter", "data_type": "metrics", "name": "otlp/elastic", "message": "unsupported data points", "dropped_data_points": 38.

1. What the number 38 means?
2. What kind of data points are unsupported?

opentelemetry-collector config:

  relay:  |
    exporters:
      debug:
        verbosity: detailed
      otlp/elastic: 
        endpoint: https://eck-apm-eck-apm-server-apm-http.log.svc.cluster.local:8200
        headers:
          Authorization: Bearer ***
        tls:
          insecure_skip_verify: true
    extensions:
      health_check:
        endpoint: ${env:MY_POD_IP}:13133
    processors:
      batch:
      batch/2:
        send_batch_size: 10000
        timeout: 10s
      memory_limiter:
        check_interval: 5s
        limit_percentage: 80
        spike_limit_percentage: 25
    receivers:
      prometheus:
        config:
          scrape_configs:
          - job_name: otc-server1
            scrape_interval: 300s
            static_configs:
            - targets:
              - server1.svc.cluster.local:9404
    service:
      extensions:
      - health_check
      pipelines:
        metrics:
          exporters:
          - debug
          - otlp/elastic
          processors:
          - memory_limiter
          - batch
          receivers:
          - prometheus
      telemetry:
        logs:
          level: "debug"      
        metrics:
          address: ${env:MY_POD_IP}:8888