原因

根據官方文檔提示：

webpack will automatically split chunks based on these conditions:
New chunk can be shared OR modules are from the node_modules folder
New chunk would be bigger than 30kb (before min+gz)
Maximum number of parallel requests when loading chunks on demand would be lower or equal to 5
Maximum number of parallel requests at initial page load would be lower or equal to 3

默認配置中公共模塊的大小要大于30kb或滿足其他條件才會進行分離

解決辦法

在webpack配置文件中設置 minisize屬性，降低打包標準

//... 其他基礎配置
optimization: {
    splitChunks: {
      // 包含所有chunks
      chunks: "all",
      automaticNameDelimiter: "-",
      minSize: 30, // 默認提取出的新chunk在兩次壓縮(打包壓縮和服務器壓縮)之前要大于30kb
    },
  },