环境信息：
1.系统：MacOS Mojave 10.14.5；
2.浏览器：Google Chrome 81.0.4044.122（正式版本，64位，目前最新）；
3.NodeJS：v12.16.2；
4.NPM：v6.14.4；
5.Yarn 镜像源地址：https://registry.npmjs.org/；
6.@vue/cli：v4.3.1；
7.Yarn：v1.5.1；

重现步骤：
1.vue create vue3-beta；
（1）Please pick a preset -> Manually select features
（2）Check the features needed for your project -> Babel，Router，Vuex，Linter / Formatter
（3）Use history mode for router? -> Y
（4）Pick a linter / formatter config -> ESLint with error prevention only
（5）Pick additional lint features -> Lint on save
（6）Where do you prefer placing config for Babel, ESLint, etc.? -> In dedicated config files
（7）Save this as a preset for future projects? -> N
2.此时yarn serve 后，更改/src/views/Home.vue 后，HMR 有效；
3.vue add vue-next；
4.此后再进行yarn serve，更改/src/views/Home.vue 后，HMR 失效；

现象：
1.HMR 失效，更改 .vue 后浏览器不会自动刷新，手动刷新后试图变更；
2.浏览器控制台，保持打印：[HMR] Waiting for update signal from WDS...，更改 .vue 后打印无变化；

附 package.json 内容：

{"name":"vue3-beta","version":"0.1.0","private":true,"scripts": {"serve":"vue-cli-service serve","build":"vue-cli-service build","lint":"vue-cli-service lint"  },"dependencies": {"core-js":"^3.6.4","vue":"^3.0.0-beta.1","vue-router":"^4.0.0-alpha.5","vuex":"^4.0.0-alpha.1"  },"devDependencies": {"@vue/cli-plugin-babel":"~4.3.0","@vue/cli-plugin-eslint":"~4.3.0","@vue/cli-plugin-router":"~4.3.0","@vue/cli-plugin-vuex":"~4.3.0","@vue/cli-service":"~4.3.0","@vue/compiler-sfc":"^3.0.0-beta.1","babel-eslint":"^10.1.0","eslint":"^6.7.2","eslint-plugin-vue":"^7.0.0-alpha.0","vue-cli-plugin-vue-next":"~0.1.2"  }}

烦请尽快解决，有什么需要配合定位的我这边尽力配合，谢谢！