Cannot see the sources in the browser inspection

[germanicus9]

In order to make some debug in the prod env I need to see webpack sources in the browser.
What is wrong here?
I have the following configuration:
webpack.prod.js

const ENV = 'production';
const extractSASS = new ExtractTextPlugin(`[name]-sass.[hash].css`);
const extractCSS = new ExtractTextPlugin(`[name].[hash].css`);
module.exports = webpackMerge(commonConfig({ env: ENV }), {
    // Enable source maps. Please note that this will slow down the build.
    // You have to enable it in UglifyJSPlugin config below and in tsconfig-aot.json as well
    devtool: 'source-map',
    entry: {
        polyfills: './src/main/webapp/app/polyfills',
        global: './src/main/webapp/content/scss/global.scss',
        main: './src/main/webapp/app/app.main'
    },
    output: {
        path: utils.root('target/classes/static/'),
        filename: 'app/[name].[hash].bundle.js',
        chunkFilename: 'app/[id].[hash].chunk.js'
    },
    module: {
        rules: [{
            test: /(?:\.ngfactory\.js|\.ngstyle\.js|\.ts)$/,
            use: [ '@ngtools/webpack' ]
        },
        {
            test: /\.scss$/,
            loaders: ['to-string-loader', 'css-loader', 'sass-loader'],
            exclude: /(vendor\.scss|global\.scss)/
        },
        {
            test: /(vendor\.scss|global\.scss)/,
            use: extractSASS.extract({
                fallback: 'style-loader',
                use: ['css-loader', 'postcss-loader', 'sass-loader']
            })
        },
        {
            test: /\.css$/,
            loaders: ['to-string-loader', 'css-loader'],
            exclude: /(vendor\.css|global\.css)/
        },
        {
            test: /(vendor\.css|global\.css)/,
            use: extractCSS.extract({
                fallback: 'style-loader',
                use: ['css-loader']
            })
        }]
    },
    plugins: [
        extractSASS,
        extractCSS,
        new Visualizer({
            // Webpack statistics in target folder
            filename: '../stats.html'
        }),
        new UglifyJSPlugin({
            parallel: true,
            uglifyOptions: {
                ie8: false,
                sourceMap: true, // Enable source maps. Please note that this will slow down the build
                compress: {
                    dead_code: true,
                    warnings: false,
                    properties: true,
                    drop_debugger: true,
                    conditionals: true,
                    booleans: true,
                    loops: true,
                    unused: true,
                    toplevel: true,
                    if_return: true,
                    inline: true,
                    join_vars: true
                },
                output: {
                    comments: false,
                    beautify: false,
                    indent_level: 2
                }
            }
        }),
        new AngularCompilerPlugin({
            mainPath: utils.root('src/main/webapp/app/app.main.ts'),
            tsConfigPath: utils.root('tsconfig-aot.json'),
            sourceMap: true
        }),
        new webpack.LoaderOptionsPlugin({
            minimize: true,
            debug: false
        })

and tsconfig-aot.json

{
    "compilerOptions": {
        "target": "es5",
        "module": "es2015",
        "moduleResolution": "node",
        "sourceMap": true,
        "emitDecoratorMetadata": true,
        "experimentalDecorators": true,
        "removeComments": false,
        "noImplicitAny": false,
        "suppressImplicitAnyIndexErrors": true,
        "skipLibCheck": true,
        "outDir": "target/classes/static/app",
        "lib": ["es2015", "dom"],
        "typeRoots": [
            "node_modules/@types"
        ]
    },
    "angularCompilerOptions": {
        "genDir": "target/aot",
        "skipMetadataEmit" : true
    }
}