Watcher webhook acked

Hi! guys
i need your help with this...
I am using the webhook api in a watcher, in my elasticcloud, but I get the following error:

{
  "watch_id": "aeffa60d-1eca-40c6-a35d-4dcfc7e450f7",
  "node": "ELuSGxpSRICZb2ZHJp4paA",
  "state": "failed",
  "user": "elastic",
  "status": {
    "state": {
      "active": true,
      "timestamp": "2021-02-22T23:36:52.408Z"
    },
    "last_checked": "2021-02-22T23:41:52.525Z",
    "last_met_condition": "2021-02-22T23:41:52.525Z",
    "actions": {
      "ack-slack": {
        "ack": {
          "timestamp": "2021-02-22T23:37:52.641Z",
          "state": "ackable"
        },
        "last_execution": {
          "timestamp": "2021-02-22T23:41:52.525Z",
          "successful": true
        },
        "last_successful_execution": {
          "timestamp": "2021-02-22T23:41:52.525Z",
          "successful": true
        }
      }
    },
    "execution_state": "failed",
    "version": -1
  },
  "trigger_event": {
    "type": "schedule",
    "triggered_time": "2021-02-22T23:42:22.565Z",
    "schedule": {
      "scheduled_time": "2021-02-22T23:42:22.410Z"
    }
  },
  "input": {
    "search": {
      "request": {
        "search_type": "query_then_fetch",
        "indices": [
          "agenteallot*"
        ],
        "rest_total_hits_as_int": true,
        "body": {
          "size": 0,
          "query": {
            "bool": {
              "filter": [
                {
                  "range": {
                    "@timestamp": {
                      "gte": "{{ctx.trigger.scheduled_time}}||-30s",
                      "lte": "{{ctx.trigger.scheduled_time}}",
                      "format": "strict_date_optional_time||basic_time_no_millis"
                    }
                  }
                },
                {
                  "term": {
                    "monitor.name.keyword": "13-3-CALLE_58-LAN-20M-99.8"
                  }
                }
              ]
            }
          },
          "aggs": {
            "metricAgg": {
              "max": {
                "field": "summary.down"
              }
            }
          }
        }
      }
    }
  },
  "condition": {
    "script": {
      "source": "if (ctx.payload.aggregations.metricAgg.value >= params.threshold) { return true; } return false;",
      "lang": "painless",
      "params": {
        "threshold": 0.8
      }
    }
  },
  "metadata": {
    "name": "Acked13-3DOWN",
    "xpack": {
      "type": "json"
    }
  },
  "result": {
    "execution_time": "2021-02-22T23:42:22.565Z",
    "execution_duration": 2,
    "input": {
      "type": "search",
      "status": "success",
      "payload": {
        "_shards": {
          "total": 1,
          "failed": 0,
          "successful": 1,
          "skipped": 0
        },
        "hits": {
          "hits": [],
          "total": 0,
          "max_score": null
        },
        "took": 1,
        "timed_out": false,
        "aggregations": {
          "metricAgg": {
            "value": null
          }
        }
      },
      "search": {
        "request": {
          "search_type": "query_then_fetch",
          "indices": [
            "agenteallot*"
          ],
          "rest_total_hits_as_int": true,
          "body": {
            "size": 0,
            "query": {
              "bool": {
                "filter": [
                  {
                    "range": {
                      "@timestamp": {
                        "gte": "2021-02-22T23:42:22.410Z||-30s",
                        "lte": "2021-02-22T23:42:22.410Z",
                        "format": "strict_date_optional_time||basic_time_no_millis"
                      }
                    }
                  },
                  {
                    "term": {
                      "monitor.name.keyword": "13-3-CALLE_58-LAN-20M-99.8"
                    }
                  }
                ]
              }
            },
            "aggs": {
              "metricAgg": {
                "max": {
                  "field": "summary.down"
                }
              }
            }
          }
        }
      }
    },
    "actions": []
  },
  "exception": {
    "type": "script_exception",
    "reason": "runtime error",
    "script_stack": [
      "if (ctx.payload.aggregations.metricAgg.value >= params.threshold) { ",
      "                                                      ^---- HERE"
    ],
    "script": "if (ctx.payload.aggregations.metricAgg.value >= params.threshold) { return true; } return false;",
    "lang": "painless",
    "position": {
      "offset": 54,
      "start": 0,
      "end": 68
    },
    "caused_by": {
      "type": "null_pointer_exception",
      "reason": "Cannot invoke \"Object.getClass()\" because \"leftObject\" is null",
      "stack_trace": "java.lang.NullPointerException: Cannot invoke \"Object.getClass()\" because \"leftObject\" is null\n\tat org.elasticsearch.painless.DefBootstrap$MIC.checkBoth(DefBootstrap.java:401)\n\tat org.elasticsearch.painless.PainlessScript$Script.execute(if (ctx.payload.aggregations.metricAgg.value >= params.threshold) { return true; } return false;:55)\n\tat org.elasticsearch.xpack.watcher.condition.ScriptCondition.doExecute(ScriptCondition.java:60)\n\tat org.elasticsearch.xpack.watcher.condition.ScriptCondition.execute(ScriptCondition.java:55)\n\tat org.elasticsearch.xpack.watcher.execution.ExecutionService.executeInner(ExecutionService.java:512)\n\tat org.elasticsearch.xpack.watcher.execution.ExecutionService.execute(ExecutionService.java:319)\n\tat org.elasticsearch.xpack.watcher.execution.ExecutionService.lambda$executeAsync$5(ExecutionService.java:420)\n\tat org.elasticsearch.xpack.watcher.execution.ExecutionService$WatchExecutionTask.run(ExecutionService.java:626)\n\tat org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingRunnable.run(ThreadContext.java:636)\n\tat java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)\n\tat java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)\n\tat java.base/java.lang.Thread.run(Thread.java:832)\n"
    },
    "stack_trace": "ScriptException[runtime error]; nested: NullPointerException[Cannot invoke \"Object.getClass()\" because \"leftObject\" is null];\n\tat org.elasticsearch.painless.PainlessScript.convertToScriptException(PainlessScript.java:96)\n\tat org.elasticsearch.painless.PainlessScript$Script.execute(if (ctx.payload.aggregations.metricAgg.value >= params.threshold) { return true; } return false;:55)\n\tat org.elasticsearch.xpack.watcher.condition.ScriptCondition.doExecute(ScriptCondition.java:60)\n\tat org.elasticsearch.xpack.watcher.condition.ScriptCondition.execute(ScriptCondition.java:55)\n\tat org.elasticsearch.xpack.watcher.execution.ExecutionService.executeInner(ExecutionService.java:512)\n\tat org.elasticsearch.xpack.watcher.execution.ExecutionService.execute(ExecutionService.java:319)\n\tat org.elasticsearch.xpack.watcher.execution.ExecutionService.lambda$executeAsync$5(ExecutionService.java:420)\n\tat org.elasticsearch.xpack.watcher.execution.ExecutionService$WatchExecutionTask.run(ExecutionService.java:626)\n\tat org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingRunnable.run(ThreadContext.java:636)\n\tat java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)\n\tat java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)\n\tat java.base/java.lang.Thread.run(Thread.java:832)\nCaused by: java.lang.NullPointerException: Cannot invoke \"Object.getClass()\" because \"leftObject\" is null\n\tat org.elasticsearch.painless.DefBootstrap$MIC.checkBoth(DefBootstrap.java:401)\n\t... 11 more\n"
  }
}

this is the line of code in my watcher :

{
  "trigger": {
    "schedule": {
      "interval": "30s"
    }
  },
  "input": {
    "search": {
      "request": {
        "search_type": "query_then_fetch",
        "indices": [
          "agenteallot*"
        ],
        "rest_total_hits_as_int": true,
        "body": {
          "size": 0,
          "query": {
            "bool": {
              "filter": [
                {
                  "range": {
                    "@timestamp": {
                      "gte": "{{ctx.trigger.scheduled_time}}||-30s",
                      "lte": "{{ctx.trigger.scheduled_time}}",
                      "format": "strict_date_optional_time||basic_time_no_millis"
                    }
                  }
                },
                {
                  "term": {
                    "monitor.name.keyword": "13-3-CALLE_58-LAN-20M-99.8"
                  }
                }
              ]
            }
          },
          "aggs": {
            "metricAgg": {
              "max": {
                "field": "summary.down"
              }
            }
          }
        }
      }
    }
  },
  "condition": {
    "script": {
      "source": "if (ctx.payload.aggregations.metricAgg.value >= params.threshold) { return true; } return false;",
      "lang": "painless",
      "params": {
        "threshold": 0.8
      }
    }
  },
  "actions": {
    "ack-slack": {
      "webhook": {
        "scheme": "https",
        "host": "425dc991b9ec4c7fb23f3ef706bd675a.us-central1.gcp.cloud.es.io",
        "port": 9243,
        "method": "post",
        "path": "/_xpack/watcher/watch/4ea38f7f-640f-4038-a2f9-79d92a8c53f2/_ack/email_1",
        "params": {},
        "headers": {},
        "auth": {
          "basic": {
            "username": "elastic",
            "password": "::es_redacted::"
          }
        }
      }
    }
  },
  "transform": {
    "script": {
      "source": "return [ 'time_triggered': Instant.ofEpochMilli(ctx.trigger.triggered_time.getMillis()).atZone(ZoneId.of('America/Bogota')).format(DateTimeFormatter.ofPattern('YYYY-MM-dd HH:mm:ss')) ];",
      "lang": "painless"
    }
  }
}

I have also noticed this error pattern, it tries to run it runs the clock fine, but then it comes out error and so on: it runs, then error, runs, then error.