KibanaがElasticsearchに接続できません

前提・実現したいこと

KibanaがElasticsearchに接続できません。

発生している問題・エラーメッセージ

Kibana起動時のエラーメッセージです。

log   [23:55:34.484] [info][plugins-service] Plugin "case" is disabled.
  log   [23:55:46.109] [info][plugins-system] Setting up [37] plugins: [siem,taskManager,licensing,infra,encryptedSavedObjects,code,usageCollection,metrics,canvas,timelion,features,security,apm_oss,translations,reporting,share,uiActions,data,navigation,status_page,newsfeed,kibana_legacy,management,dev_tools,inspector,expressions,visualizations,embeddable,advancedUiActions,dashboard_embeddable_container,eui_utils,home,spaces,apm,cloud,graph,bfetch]
  log   [23:55:46.111] [info][plugins][siem] Setting up plugin
  log   [23:55:46.112] [info][plugins][taskManager] Setting up plugin
  log   [23:55:46.138] [info][licensing][plugins] Setting up plugin
  log   [23:55:46.143] [info][infra][plugins] Setting up plugin
  log   [23:55:46.144] [info][encryptedSavedObjects][plugins] Setting up plugin
  log   [23:55:46.145] [warning][config][encryptedSavedObjects][plugins] Generating a random key for xpack.encryptedSavedObjects.encryptionKey. To be able to decrypt encrypted saved objects attributes after restart, please set xpack.encryptedSavedObjects.encryptionKey in kibana.yml
  log   [23:55:46.153] [info][code][plugins] Setting up plugin
  log   [23:55:46.154] [info][plugins][usageCollection] Setting up plugin
  log   [23:55:46.157] [info][metrics][plugins] Setting up plugin
  log   [23:55:46.157] [info][canvas][plugins] Setting up plugin
  log   [23:55:46.165] [info][plugins][timelion] Setting up plugin
  log   [23:55:46.167] [info][features][plugins] Setting up plugin
  log   [23:55:46.168] [info][plugins][security] Setting up plugin
  log   [23:55:46.169] [warning][config][plugins][security] Generating a random key for xpack.security.encryptionKey. To prevent sessions from being invalidated on restart, please set xpack.security.encryptionKey in kibana.yml
  log   [23:55:46.170] [warning][config][plugins][security] Session cookies will be transmitted over insecure connections. This is not recommended.
  log   [23:55:46.198] [info][apm_oss][plugins] Setting up plugin
  log   [23:55:46.198] [info][plugins][translations] Setting up plugin
  log   [23:55:46.199] [info][plugins][share] Setting up plugin
  log   [23:55:46.201] [info][data][plugins] Setting up plugin
  log   [23:55:46.209] [info][home][plugins] Setting up plugin
  log   [23:55:46.218] [info][plugins][spaces] Setting up plugin
  log   [23:55:46.224] [info][apm][plugins] Setting up plugin
  log   [23:55:46.231] [info][cloud][plugins] Setting up plugin
  log   [23:55:46.232] [info][graph][plugins] Setting up plugin
  log   [23:55:46.236] [info][bfetch][plugins] Setting up plugin
  log   [23:55:46.248] [info][savedobjects-service] Waiting until all Elasticsearch nodes are compatible with Kibana before starting saved objects migrations...
  log   [23:55:46.317] [info][savedobjects-service] Starting saved objects migrations
Could not create APM Agent configuration: Request Timeout after 30000ms
  log   [23:56:16.323] [warning][savedobjects-service] Unable to connect to Elasticsearch. Error: Request Timeout after 30000ms
  log   [00:15:13.879] [warning][savedobjects-service] Unable to connect to Elasticsearch. Error: [master_not_discovered_exception] null

該当のソースコード

kibana.yml を編集した項目

server.port: 5601
server.host: "0.0.0.0"
elasticsearch.hosts: ["http://127.0.0.1:9200"]

elasticsearch.yml の編集した項目

network.host: 0.0.0.0
discovery.seed_hosts: ["127.0.0.1:9200"]

試したこと

curlでelasticsearchに接続したところ、正常に接続できました。

$ curl -XGET 127.0.0.1:9200
{
  "name" : "elastic",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "_na_",
  "version" : {
    "number" : "7.6.2",
    "build_flavor" : "default",
    "build_type" : "deb",
    "build_hash" : "ef48eb35cf30adf4db14086e8aabd07ef6fb113f",
    "build_date" : "2020-03-26T06:34:37.794943Z",
    "build_snapshot" : false,
    "lucene_version" : "8.4.0",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}

curlで接続はできますが、Kibanaからの接続が失敗してしまう状況です。
どなたかお力添えをお願いいたします。