Добавил очистку publicDir

build/webpack.prod.config.js

@@ -1,3 +1,4 @@
+const fs = require('fs-extra');
 const path = require('path');
 //const webpack = require('webpack');
 
@@ -12,6 +13,8 @@ const CopyWebpackPlugin = require('copy-webpack-plugin');
 const publicDir = path.resolve(__dirname, '../dist/tmp/public');
 const clientDir = path.resolve(__dirname, '../client');
 
+fs.emptyDirSync(publicDir);
+
 module.exports = merge(baseWpConfig, {
     mode: 'production',
     output: {
@@ -44,7 +47,6 @@ module.exports = merge(baseWpConfig, {
         ]
     },
     plugins: [
-        //new CleanWebpackPlugin({ cleanOnceBeforeBuildPatterns: [`${publicDir}/**`] }),
         new MiniCssExtractPlugin({
             filename: "[name].[contenthash].css"
         }),