配置postcss-px2rem时遇到的小BUG

{
                        test: /\\.(css|less)$/,
                        exclude:/node_modules/,
                        use: [
                            require.resolve(\'style-loader\'),
                            {
                                loader: require.resolve(\'css-loader\'),
                                options: {
                                    importLoaders: 1,
                                    modules: true,
                                    localIdentName: \'[local]-[hash: 64:5]\'
                                },
                            },
                            {
                                loader: require.resolve(\'postcss-loader\'),
                                options: {
                                    // Necessary for external CSS imports to work
                                    // https://github.com/facebookincubator/create-react-app/issues/2677
                                    ident: \'postcss\',
                                    plugins: () => [
                                        require(\'postcss-flexbugs-fixes\'),
                                        autoprefixer({
                                            browsers: [
                                                \'>1%\',
                                                \'last 4 versions\',
                                                \'Firefox ESR\',
                                                \'not ie < 9\', // React doesn\'t support IE8 anyway
                                            ],
                                            flexbox: \'no-2009\',
                                        }),
                                        px2rem({
                                            \"rootValue\": 50,
                                            \"propList\": [
                                                \"*\"
                                            ]
                                        })
                                    ],
                                },
                            },
                            {
                                loader: require.resolve(\"less-loader\")
                            }
                        ],
                    },
                     {
                        test: /\\.(css|less)$/,
                        include:/node_modules/,
                        use: [
                            require.resolve(\'style-loader\'),
                            {
                                loader: require.resolve(\'css-loader\'),
                                options: {
                                    importLoaders: 1,
                                },
                            },
                            {
                                loader: require.resolve(\'postcss-loader\'),
                                options: {
                                    // Necessary for external CSS imports to work
                                    // https://github.com/facebookincubator/create-react-app/issues/2677
                                    ident: \'postcss\',
                                    plugins: () => [
                                        require(\'postcss-flexbugs-fixes\'),
                                        autoprefixer({
                                            browsers: [
                                                \'>1%\',
                                                \'last 4 versions\',
                                                \'Firefox ESR\',
                                                \'not ie < 9\', // React doesn\'t support IE8 anyway
                                            ],
                                            flexbox: \'no-2009\',
                                        }),
                                        px2rem({
                                            \"rootValue\": 50,
                                            \"propList\": [
                                                \"*\"
                                            ]
                                        })
                                    ],
                                },
                            },
                            {
                                loader: require.resolve(\"less-loader\")
                            }
                        ],
                    }

webpack在moudle.rule里配置postcss时
发现在 第二个对象里 include:/node_modules/ 里配置px2rem才起作用,且是全局作用。
但css-loader里配置项modules: true 样式模块功能运行正常?
难道postcss-loader是单例模式?