Traffic produced by Xray

[schmidt9]

I installed Xray with the following config on a VPS and noticed that it instantly produces queries to the host I specified in dest and serverNames on different ports, even with no clients connections, it can be seen with netstat, iftop etc. This gives several hundreds of megabytes rx/tx traffic per day (as reported by vnstat). Could you please explain why it happens? Why should Xray query masking host all the time?

my config

{
  "log": {
    "loglevel": "info"
  },
  "inbounds": [
    {
      "listen": "my server ip",
      "port": 443,
      "protocol": "vless",
      "tag": "reality-in",
      "settings": {
        "clients": [
          {
            "id": "my_UUID",
            "email": "user1",
            "flow": "xtls-rprx-vision"
          }
        ],
        "decryption": "none"
      },
      "streamSettings": {
        "network": "tcp",
        "security": "reality",
        "realitySettings": {
          "show": false,
          "dest": "maskdomain:443",
          "xver": 0,
          "serverNames": [
            "maskdomain"
          ],
          "privateKey": "my_key",
          "minClientVer": "",
          "maxClientVer": "",
          "maxTimeDiff": 0,
          "shortIds": [
            ""
          ]
        }
      },
      "sniffing": {
        "enabled": true,
        "destOverride": [
          "http",
          "tls",
          "quic"
        ]
      }
    }
  ],
  "outbounds": [
    {
      "protocol": "freedom",
      "tag": "direct"
    },
    {
      "protocol": "blackhole",
      "tag": "block"
    }
  ],
  "routing": {
    "rules": [
      {
        "type": "field",
        "protocol": "bittorrent",
        "outboundTag": "block"
      }
    ],
    "domainStrategy": "IPIfNonMatch"
  }
}