Metabase is sending alerts half an hour after it is actually scheduled to send alerts

Metabase keeps sending alerts half an hour after it is supposed to. It is hosted directly on an ec2 instance running linux without using docker container.
These are the configuration for the instance

{
  "browser-info": {
    "language": "en-GB",
    "platform": "Linux x86_64",
    "userAgent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36",
    "vendor": "Google Inc."
  },
  "system-info": {
    "file.encoding": "UTF-8",
    "java.runtime.name": "OpenJDK Runtime Environment",
    "java.runtime.version": "11.0.21+9-post-Ubuntu-0ubuntu120.04",
    "java.vendor": "Ubuntu",
    "java.vendor.url": "https://ubuntu.com/",
    "java.version": "11.0.21",
    "java.vm.name": "OpenJDK 64-Bit Server VM",
    "java.vm.version": "11.0.21+9-post-Ubuntu-0ubuntu120.04",
    "os.name": "Linux",
    "os.version": "5.15.0-1038-gcp",
    "user.language": "en",
    "user.timezone": "Etc/UTC"
  },
  "metabase-info": {
    "databases": [
      "postgres",
      "bigquery-cloud-sdk",
      "athena"
    ],
    "hosting-env": "unknown",
    "application-database": "h2",
    "application-database-details": {
      "database": {
        "name": "H2",
        "version": "2.1.212 (2022-04-09)"
      },
      "jdbc-driver": {
        "name": "H2 JDBC Driver",
        "version": "2.1.212 (2022-04-09)"
      }
    },
    "run-mode": "prod",
    "version": {
      "date": "2023-07-28",
      "tag": "v1.46.6.4",
      "branch": "release-x.46.6.x",
      "hash": "7c60aca"
    },
    "settings": {
      "report-timezone": "Asia/Kolkata"
    }
  }
}

The logs also don't indicate any issues but duly post half an hour after it is configured to. I have also tried changing the timezone but the issue persists.
Please let me know if any other details are required.